fix: Always explicitly set encoding for text files (fixes #8263)

79 files changed, 310 insertions, 305 deletions

diff --git a/ci/ciimage/build.py b/ci/ciimage/build.py
index dcc11a9..2cf0736 100755
--- a/ci/ciimage/build.py
+++ b/ci/ciimage/build.py
@@ -18,7 +18,7 @@ install_script = 'install.sh'
 class ImageDef:
     def __init__(self, image_dir: Path) -> None:
         path = image_dir / image_def_file
-        data = json.loads(path.read_text())
+        data = json.loads(path.read_text(encoding='utf-8'))
 
         assert isinstance(data, dict)
         assert all([x in data for x in ['base_image', 'env']])
@@ -74,7 +74,7 @@ class Builder(BuilderBase):
         # Also add /ci to PATH
         out_data += 'export PATH="/ci:$PATH"\n'
 
-        out_file.write_text(out_data)
+        out_file.write_text(out_data, encoding='utf-8')
 
         # make it executable
         mode = out_file.stat().st_mode
@@ -91,7 +91,7 @@ class Builder(BuilderBase):
             RUN /ci/install.sh
         ''')
 
-        out_file.write_text(out_data)
+        out_file.write_text(out_data, encoding='utf-8')
 
     def do_build(self) -> None:
         # copy files
@@ -131,7 +131,7 @@ class ImageTester(BuilderBase):
             ADD meson /meson
         ''')
 
-        out_file.write_text(out_data)
+        out_file.write_text(out_data, encoding='utf-8')
 
     def copy_meson(self) -> None:
         shutil.copytree(
diff --git a/docs/genrelnotes.py b/docs/genrelnotes.py
index 5dad924..082ab45 100755
--- a/docs/genrelnotes.py
+++ b/docs/genrelnotes.py
@@ -36,10 +36,10 @@ def add_to_sitemap(from_version, to_version):
        Adds release note entry to sitemap.txt.
     '''
     sitemapfile = '../sitemap.txt'
-    s_f = open(sitemapfile)
+    s_f = open(sitemapfile, encoding='utf-8')
     lines = s_f.readlines()
     s_f.close()
-    with open(sitemapfile, 'w') as s_f:
+    with open(sitemapfile, 'w', encoding='utf-8') as s_f:
         for line in lines:
             if 'Release-notes' in line and from_version in line:
                 new_line = line.replace(from_version, to_version)
@@ -51,10 +51,10 @@ def generate(from_version, to_version):
        Generate notes for Meson build next release.
     '''
     ofilename = f'Release-notes-for-{to_version}.md'
-    with open(ofilename, 'w') as ofile:
+    with open(ofilename, 'w', encoding='utf-8') as ofile:
         ofile.write(RELNOTE_TEMPLATE.format(to_version, to_version))
         for snippetfile in glob('snippets/*.md'):
-            snippet = open(snippetfile).read()
+            snippet = open(snippetfile, encoding='utf-8').read()
             ofile.write(snippet)
             if not snippet.endswith('\n'):
                 ofile.write('\n')
diff --git a/mesonbuild/ast/interpreter.py b/mesonbuild/ast/interpreter.py
index b9dfc7b..99c6979 100644
--- a/mesonbuild/ast/interpreter.py
+++ b/mesonbuild/ast/interpreter.py
@@ -179,7 +179,7 @@ class AstInterpreter(InterpreterBase):
         if not os.path.isfile(absname):
             sys.stderr.write(f'Unable to find build file {buildfilename} --> Skipping\n')
             return
-        with open(absname, encoding='utf8') as f:
+        with open(absname, encoding='utf-8') as f:
             code = f.read()
         assert(isinstance(code, str))
         try:
diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index c489dce..21a6c83 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -374,7 +374,7 @@ class Backend:
             if not os.path.exists(outfileabs_tmp_dir):
                 os.makedirs(outfileabs_tmp_dir)
             result.append(unity_src)
-            return open(outfileabs_tmp, 'w')
+            return open(outfileabs_tmp, 'w', encoding='utf-8')
 
         # For each language, generate unity source files and return the list
         for comp, srcs in compsrcs.items():
@@ -765,7 +765,7 @@ class Backend:
 
         content = f'#include "{os.path.basename(pch_header)}"'
         pch_file_tmp = pch_file + '.tmp'
-        with open(pch_file_tmp, 'w') as f:
+        with open(pch_file_tmp, 'w', encoding='utf-8') as f:
             f.write(content)
         mesonlib.replace_if_different(pch_file, pch_file_tmp)
         return pch_rel_to_build
@@ -1019,7 +1019,7 @@ class Backend:
         ifilename = os.path.join(self.environment.get_build_dir(), 'depmf.json')
         ofilename = os.path.join(self.environment.get_prefix(), self.build.dep_manifest_name)
         mfobj = {'type': 'dependency manifest', 'version': '1.0', 'projects': self.build.dep_manifest}
-        with open(ifilename, 'w') as f:
+        with open(ifilename, 'w', encoding='utf-8') as f:
             f.write(json.dumps(mfobj))
         # Copy file from, to, and with mode unchanged
         d.data.append(InstallDataBase(ifilename, ofilename, None, ''))
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 192cef3..597789b 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -20,6 +20,7 @@ import subprocess
 from collections import OrderedDict
 from enum import Enum, unique
 import itertools
+from textwrap import dedent
 from pathlib import PurePath, Path
 from functools import lru_cache
 
@@ -462,10 +463,11 @@ class NinjaBackend(backends.Backend):
             return open(tempfilename, 'a', encoding='utf-8')
         filename = os.path.join(self.environment.get_scratch_dir(),
                                 'incdetect.c')
-        with open(filename, 'w') as f:
-            f.write('''#include<stdio.h>
-int dummy;
-''')
+        with open(filename, 'w', encoding='utf-8') as f:
+            f.write(dedent('''\
+                #include<stdio.h>
+                int dummy;
+            '''))
 
         # The output of cl dependency information is language
         # and locale dependent. Any attempt at converting it to
@@ -1215,7 +1217,7 @@ int dummy;
         manifest_path = os.path.join(self.get_target_private_dir(target), 'META-INF', 'MANIFEST.MF')
         manifest_fullpath = os.path.join(self.environment.get_build_dir(), manifest_path)
         os.makedirs(os.path.dirname(manifest_fullpath), exist_ok=True)
-        with open(manifest_fullpath, 'w') as manifest:
+        with open(manifest_fullpath, 'w', encoding='utf-8') as manifest:
             if any(target.link_targets):
                 manifest.write('Class-Path: ')
                 cp_paths = [os.path.join(self.get_target_dir(l), l.get_filename()) for l in target.link_targets]
diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index 5595fd0..7fcc324 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -206,7 +206,7 @@ class Vs2010Backend(backends.Backend):
 
     @staticmethod
     def touch_regen_timestamp(build_dir: str) -> None:
-        with open(Vs2010Backend.get_regen_stampfile(build_dir), 'w'):
+        with open(Vs2010Backend.get_regen_stampfile(build_dir), 'w', encoding='utf-8'):
             pass
 
     def get_vcvars_command(self):
diff --git a/mesonbuild/cmake/fileapi.py b/mesonbuild/cmake/fileapi.py
index 6773e9a..5d4d01a 100644
--- a/mesonbuild/cmake/fileapi.py
+++ b/mesonbuild/cmake/fileapi.py
@@ -51,7 +51,7 @@ class CMakeFileAPI:
         }
 
         query_file = self.request_dir / 'query.json'
-        query_file.write_text(json.dumps(query, indent=2))
+        query_file.write_text(json.dumps(query, indent=2), encoding='utf-8')
 
     def load_reply(self) -> None:
         if not self.reply_dir.is_dir():
@@ -75,7 +75,7 @@ class CMakeFileAPI:
         # Debug output
         debug_json = self.build_dir / '..' / 'fileAPI.json'
         debug_json = debug_json.resolve()
-        debug_json.write_text(json.dumps(index, indent=2))
+        debug_json.write_text(json.dumps(index, indent=2), encoding='utf-8')
         mlog.cmd_ci_include(debug_json.as_posix())
 
         # parse the JSON
@@ -313,7 +313,7 @@ class CMakeFileAPI:
         if not real_path.exists():
             raise CMakeException(f'File "{real_path}" does not exist')
 
-        data = json.loads(real_path.read_text())
+        data = json.loads(real_path.read_text(encoding='utf-8'))
         assert isinstance(data, dict)
         for i in data.keys():
             assert isinstance(i, str)
diff --git a/mesonbuild/cmake/toolchain.py b/mesonbuild/cmake/toolchain.py
index f3e487d..1a6dcf0 100644
--- a/mesonbuild/cmake/toolchain.py
+++ b/mesonbuild/cmake/toolchain.py
@@ -66,8 +66,8 @@ class CMakeToolchain:
     def write(self) -> Path:
         if not self.toolchain_file.parent.exists():
             self.toolchain_file.parent.mkdir(parents=True)
-        self.toolchain_file.write_text(self.generate())
-        self.cmcache_file.write_text(self.generate_cache())
+        self.toolchain_file.write_text(self.generate(), encoding='utf-8')
+        self.cmcache_file.write_text(self.generate_cache(), encoding='utf-8')
         mlog.cmd_ci_include(self.toolchain_file.as_posix())
         return self.toolchain_file
 
@@ -215,11 +215,11 @@ class CMakeToolchain:
         build_dir = Path(self.env.scratch_dir) / '__CMake_compiler_info__'
         build_dir.mkdir(parents=True, exist_ok=True)
         cmake_file = build_dir / 'CMakeLists.txt'
-        cmake_file.write_text(cmake_content)
+        cmake_file.write_text(cmake_content, encoding='utf-8')
 
         # Generate the temporary toolchain file
         temp_toolchain_file = build_dir / 'CMakeMesonTempToolchainFile.cmake'
-        temp_toolchain_file.write_text(CMakeToolchain._print_vars(self.variables))
+        temp_toolchain_file.write_text(CMakeToolchain._print_vars(self.variables), encoding='utf-8')
 
         # Configure
         trace = CMakeTraceParser(self.cmakebin.version(), build_dir)
diff --git a/mesonbuild/cmake/traceparser.py b/mesonbuild/cmake/traceparser.py
index 23a1852..42ceec6 100644
--- a/mesonbuild/cmake/traceparser.py
+++ b/mesonbuild/cmake/traceparser.py
@@ -158,7 +158,7 @@ class CMakeTraceParser:
         if not self.requires_stderr():
             if not self.trace_file_path.exists and not self.trace_file_path.is_file():
                 raise CMakeException('CMake: Trace file "{}" not found'.format(str(self.trace_file_path)))
-            trace = self.trace_file_path.read_text(errors='ignore')
+            trace = self.trace_file_path.read_text(errors='ignore', encoding='utf-8')
         if not trace:
             raise CMakeException('CMake: The CMake trace was not provided or is empty')
 
diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index ff87819..52529f7 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -765,14 +765,14 @@ class Compiler(HoldableObject, metaclass=abc.ABCMeta):
             if isinstance(code, str):
                 srcname = os.path.join(tmpdirname,
                                     'testfile.' + self.default_suffix)
-                with open(srcname, 'w') as ofile:
+                with open(srcname, 'w', encoding='utf-8') as ofile:
                     ofile.write(code)
                 # ccache would result in a cache miss
                 no_ccache = True
                 contents = code
             elif isinstance(code, mesonlib.File):
                 srcname = code.fname
-                with open(code.fname) as f:
+                with open(code.fname, encoding='utf-8') as f:
                     contents = f.read()
 
             # Construct the compiler command-line
diff --git a/mesonbuild/compilers/cs.py b/mesonbuild/compilers/cs.py
index 218942c..7ebb66d 100644
--- a/mesonbuild/compilers/cs.py
+++ b/mesonbuild/compilers/cs.py
@@ -87,7 +87,7 @@ class CsCompiler(BasicLinkerIsCompilerMixin, Compiler):
         src = 'sanity.cs'
         obj = 'sanity.exe'
         source_name = os.path.join(work_dir, src)
-        with open(source_name, 'w') as ofile:
+        with open(source_name, 'w', encoding='utf-8') as ofile:
             ofile.write(textwrap.dedent('''
                 public class Sanity {
                     static public void Main () {
diff --git a/mesonbuild/compilers/cuda.py b/mesonbuild/compilers/cuda.py
index 145b7c8..4c0d0a6 100644
--- a/mesonbuild/compilers/cuda.py
+++ b/mesonbuild/compilers/cuda.py
@@ -504,7 +504,7 @@ class CudaCompiler(Compiler):
         binname += '_cross' if self.is_cross else ''
         source_name = os.path.join(work_dir, sname)
         binary_name = os.path.join(work_dir, binname + '.exe')
-        with open(source_name, 'w') as ofile:
+        with open(source_name, 'w', encoding='utf-8') as ofile:
             ofile.write(code)
 
         # The Sanity Test for CUDA language will serve as both a sanity test
diff --git a/mesonbuild/compilers/d.py b/mesonbuild/compilers/d.py
index 78d0f62..b5ec905 100644
--- a/mesonbuild/compilers/d.py
+++ b/mesonbuild/compilers/d.py
@@ -535,7 +535,7 @@ class DCompiler(Compiler):
     def sanity_check(self, work_dir: str, environment: 'Environment') -> None:
         source_name = os.path.join(work_dir, 'sanity.d')
         output_name = os.path.join(work_dir, 'dtest')
-        with open(source_name, 'w') as ofile:
+        with open(source_name, 'w', encoding='utf-8') as ofile:
             ofile.write('''void main() { }''')
         pc = subprocess.Popen(self.exelist + self.get_output_args(output_name) + self._get_target_arch_args() + [source_name], cwd=work_dir)
         pc.wait()
diff --git a/mesonbuild/compilers/fortran.py b/mesonbuild/compilers/fortran.py
index 8264638..925eff6 100644
--- a/mesonbuild/compilers/fortran.py
+++ b/mesonbuild/compilers/fortran.py
@@ -71,7 +71,7 @@ class FortranCompiler(CLikeCompiler, Compiler):
         if binary_name.is_file():
             binary_name.unlink()
 
-        source_name.write_text('print *, "Fortran compilation is working."; end')
+        source_name.write_text('print *, "Fortran compilation is working."; end', encoding='utf-8')
 
         extra_flags: T.List[str] = []
         extra_flags += environment.coredata.get_external_args(self.for_machine, self.language)
diff --git a/mesonbuild/compilers/java.py b/mesonbuild/compilers/java.py
index 77e1a9b..ab82450 100644
--- a/mesonbuild/compilers/java.py
+++ b/mesonbuild/compilers/java.py
@@ -70,7 +70,7 @@ class JavaCompiler(BasicLinkerIsCompilerMixin, Compiler):
         src = 'SanityCheck.java'
         obj = 'SanityCheck'
         source_name = os.path.join(work_dir, src)
-        with open(source_name, 'w') as ofile:
+        with open(source_name, 'w', encoding='utf-8') as ofile:
             ofile.write(textwrap.dedent(
                 '''class SanityCheck {
                   public static void main(String[] args) {
diff --git a/mesonbuild/compilers/mixins/clike.py b/mesonbuild/compilers/mixins/clike.py
index 3210dd7..09ad837 100644
--- a/mesonbuild/compilers/mixins/clike.py
+++ b/mesonbuild/compilers/mixins/clike.py
@@ -306,7 +306,7 @@ class CLikeCompiler(Compiler):
         binname += '.exe'
         # Write binary check source
         binary_name = os.path.join(work_dir, binname)
-        with open(source_name, 'w') as ofile:
+        with open(source_name, 'w', encoding='utf-8') as ofile:
             ofile.write(code)
         # Compile sanity check
         # NOTE: extra_flags must be added at the end. On MSVC, it might contain a '/link' argument
diff --git a/mesonbuild/compilers/rust.py b/mesonbuild/compilers/rust.py
index 6a7bd04..2b566c8 100644
--- a/mesonbuild/compilers/rust.py
+++ b/mesonbuild/compilers/rust.py
@@ -65,7 +65,7 @@ class RustCompiler(Compiler):
     def sanity_check(self, work_dir: str, environment: 'Environment') -> None:
         source_name = os.path.join(work_dir, 'sanity.rs')
         output_name = os.path.join(work_dir, 'rusttest')
-        with open(source_name, 'w') as ofile:
+        with open(source_name, 'w', encoding='utf-8') as ofile:
             ofile.write(textwrap.dedent(
                 '''fn main() {
                 }
diff --git a/mesonbuild/compilers/swift.py b/mesonbuild/compilers/swift.py
index 7b18591..2d52e21 100644
--- a/mesonbuild/compilers/swift.py
+++ b/mesonbuild/compilers/swift.py
@@ -107,7 +107,7 @@ class SwiftCompiler(Compiler):
             extra_flags += self.get_compile_only_args()
         else:
             extra_flags += environment.coredata.get_external_link_args(self.for_machine, self.language)
-        with open(source_name, 'w') as ofile:
+        with open(source_name, 'w', encoding='utf-8') as ofile:
             ofile.write('''print("Swift compilation is working.")
 ''')
         pc = subprocess.Popen(self.exelist + extra_flags + ['-emit-executable', '-o', output_name, src], cwd=work_dir)
diff --git a/mesonbuild/coredata.py b/mesonbuild/coredata.py
index a0ee7df..97edeb2 100644
--- a/mesonbuild/coredata.py
+++ b/mesonbuild/coredata.py
@@ -481,8 +481,8 @@ class CoreData:
                     # the contents of that file into the meson private (scratch)
                     # directory so that it can be re-read when wiping/reconfiguring
                     copy = os.path.join(scratch_dir, f'{uuid.uuid4()}.{ftype}.ini')
-                    with open(f) as rf:
-                        with open(copy, 'w') as wf:
+                    with open(f, encoding='utf-8') as rf:
+                        with open(copy, 'w', encoding='utf-8') as wf:
                             wf.write(rf.read())
                     real.append(copy)
 
@@ -973,7 +973,7 @@ def write_cmd_line_file(build_dir: str, options: argparse.Namespace) -> None:
 
     config['options'] = {str(k): str(v) for k, v in options.cmd_line_options.items()}
     config['properties'] = properties
-    with open(filename, 'w') as f:
+    with open(filename, 'w', encoding='utf-8') as f:
         config.write(f)
 
 def update_cmd_line_file(build_dir: str, options: argparse.Namespace):
@@ -981,7 +981,7 @@ def update_cmd_line_file(build_dir: str, options: argparse.Namespace):
     config = CmdLineFileParser()
     config.read(filename)
     config['options'].update({str(k): str(v) for k, v in options.cmd_line_options.items()})
-    with open(filename, 'w') as f:
+    with open(filename, 'w', encoding='utf-8') as f:
         config.write(f)
 
 def get_cmd_line_options(build_dir: str, options: argparse.Namespace) -> str:
diff --git a/mesonbuild/dependencies/boost.py b/mesonbuild/dependencies/boost.py
index dc317cd..4e5af90 100644
--- a/mesonbuild/dependencies/boost.py
+++ b/mesonbuild/dependencies/boost.py
@@ -717,7 +717,7 @@ class BoostDependency(SystemDependency):
         # also work, however, this is slower (since it the compiler has to be
         # invoked) and overkill since the layout of the header is always the same.
         assert hfile.exists()
-        raw = hfile.read_text()
+        raw = hfile.read_text(encoding='utf-8')
         m = re.search(r'#define\s+BOOST_VERSION\s+([0-9]+)', raw)
         if not m:
             mlog.debug(f'Failed to extract version information from {hfile}')
diff --git a/mesonbuild/dependencies/cmake.py b/mesonbuild/dependencies/cmake.py
index 7dee62e..8219cc5 100644
--- a/mesonbuild/dependencies/cmake.py
+++ b/mesonbuild/dependencies/cmake.py
@@ -620,7 +620,7 @@ class CMakeDependency(ExternalDependency):
         """).format(' '.join(cmake_language)) + cmake_txt
 
         cm_file = build_dir / 'CMakeLists.txt'
-        cm_file.write_text(cmake_txt)
+        cm_file.write_text(cmake_txt, encoding='utf-8')
         mlog.cmd_ci_include(cm_file.absolute().as_posix())
 
         return build_dir
diff --git a/mesonbuild/dependencies/cuda.py b/mesonbuild/dependencies/cuda.py
index 43bb622..21cc7ab 100644
--- a/mesonbuild/dependencies/cuda.py
+++ b/mesonbuild/dependencies/cuda.py
@@ -184,7 +184,7 @@ class CudaDependency(SystemDependency):
     def _read_cuda_runtime_api_version(self, path_str: str) -> T.Optional[str]:
         path = Path(path_str)
         for i in path.rglob('cuda_runtime_api.h'):
-            raw = i.read_text()
+            raw = i.read_text(encoding='utf-8')
             m = self.cudart_version_regex.search(raw)
             if not m:
                 continue
@@ -202,7 +202,7 @@ class CudaDependency(SystemDependency):
         # Read 'version.txt' at the root of the CUDA Toolkit directory to determine the tookit version
         version_file_path = os.path.join(path, 'version.txt')
         try:
-            with open(version_file_path) as version_file:
+            with open(version_file_path, encoding='utf-8') as version_file:
                 version_str = version_file.readline() # e.g. 'CUDA Version 10.1.168'
                 m = self.toolkit_version_regex.match(version_str)
                 if m:
diff --git a/mesonbuild/dependencies/pkgconfig.py b/mesonbuild/dependencies/pkgconfig.py
index be5412e..1e8d913 100644
--- a/mesonbuild/dependencies/pkgconfig.py
+++ b/mesonbuild/dependencies/pkgconfig.py
@@ -423,7 +423,7 @@ class PkgConfigDependency(ExternalDependency):
         return out.strip()
 
     def extract_field(self, la_file: str, fieldname: str) -> T.Optional[str]:
-        with open(la_file) as f:
+        with open(la_file, encoding='utf-8') as f:
             for line in f:
                 arr = line.strip().split('=')
                 if arr[0] == fieldname:
diff --git a/mesonbuild/interpreter/interpreter.py b/mesonbuild/interpreter/interpreter.py
index e4fb0d4..1a9872d 100644
--- a/mesonbuild/interpreter/interpreter.py
+++ b/mesonbuild/interpreter/interpreter.py
@@ -973,7 +973,7 @@ external dependencies (including libraries) must go to "dependencies".''')
                 ast.accept(printer)
                 printer.post_process()
                 meson_filename = os.path.join(self.build.environment.get_build_dir(), subdir, 'meson.build')
-                with open(meson_filename, "w") as f:
+                with open(meson_filename, "w", encoding='utf-8') as f:
                     f.write(printer.result)
 
                 mlog.log('Build file:', meson_filename)
@@ -1964,7 +1964,7 @@ This will become a hard error in the future.''' % kwargs['input'], location=self
         if not os.path.isfile(absname):
             self.subdir = prev_subdir
             raise InterpreterException(f"Non-existent build file '{buildfilename!s}'")
-        with open(absname, encoding='utf8') as f:
+        with open(absname, encoding='utf-8') as f:
             code = f.read()
         assert(isinstance(code, str))
         try:
@@ -2198,7 +2198,7 @@ This will become a hard error in the future.''' % kwargs['input'], location=self
                 mesonlib.replace_if_different(ofile_abs, dst_tmp)
             if depfile:
                 mlog.log('Reading depfile:', mlog.bold(depfile))
-                with open(depfile) as f:
+                with open(depfile, encoding='utf-8') as f:
                     df = DepFile(f.readlines())
                     deps = df.get_all_dependencies(ofile_fname)
                     for dep in deps:
diff --git a/mesonbuild/interpreterbase/interpreterbase.py b/mesonbuild/interpreterbase/interpreterbase.py
index 3f5726b..d66fb9c 100644
--- a/mesonbuild/interpreterbase/interpreterbase.py
+++ b/mesonbuild/interpreterbase/interpreterbase.py
@@ -95,7 +95,7 @@ class InterpreterBase:
         mesonfile = os.path.join(self.source_root, self.subdir, environment.build_filename)
         if not os.path.isfile(mesonfile):
             raise InvalidArguments('Missing Meson file in %s' % mesonfile)
-        with open(mesonfile, encoding='utf8') as mf:
+        with open(mesonfile, encoding='utf-8') as mf:
             code = mf.read()
         if code.isspace():
             raise InvalidCode('Builder file is empty.')
diff --git a/mesonbuild/mcompile.py b/mesonbuild/mcompile.py
index d6f54e3..6e526f6 100644
--- a/mesonbuild/mcompile.py
+++ b/mesonbuild/mcompile.py
@@ -58,7 +58,7 @@ def parse_introspect_data(builddir: Path) -> T.Dict[str, T.List[dict]]:
     path_to_intro = builddir / 'meson-info' / 'intro-targets.json'
     if not path_to_intro.exists():
         raise MesonException(f'`{path_to_intro.name}` is missing! Directory is not configured yet?')
-    with path_to_intro.open() as f:
+    with path_to_intro.open(encoding='utf-8') as f:
         schema = json.load(f)
 
     parsed_data = defaultdict(list) # type: T.Dict[str, T.List[dict]]
diff --git a/mesonbuild/mdist.py b/mesonbuild/mdist.py
index 397f8cd..22196d8 100644
--- a/mesonbuild/mdist.py
+++ b/mesonbuild/mdist.py
@@ -49,7 +49,7 @@ def create_hash(fname):
     hashname = fname + '.sha256sum'
     m = hashlib.sha256()
     m.update(open(fname, 'rb').read())
-    with open(hashname, 'w') as f:
+    with open(hashname, 'w', encoding='utf-8') as f:
         # A space and an asterisk because that is the format defined by GNU coreutils
         # and accepted by busybox and the Perl shasum tool.
         f.write('{} *{}\n'.format(m.hexdigest(), os.path.basename(fname)))
@@ -67,7 +67,7 @@ def process_submodules(dirname):
     if not os.path.exists(module_file):
         return
     subprocess.check_call(['git', 'submodule', 'update', '--init', '--recursive'], cwd=dirname)
-    for line in open(module_file):
+    for line in open(module_file, encoding='utf-8'):
         line = line.strip()
         if '=' not in line:
             continue
@@ -242,7 +242,7 @@ def check_dist(packagename, meson_command, extra_meson_args, bld_root, privdir):
     unpacked_files = glob(os.path.join(unpackdir, '*'))
     assert(len(unpacked_files) == 1)
     unpacked_src_dir = unpacked_files[0]
-    with open(os.path.join(bld_root, 'meson-info', 'intro-buildoptions.json')) as boptions:
+    with open(os.path.join(bld_root, 'meson-info', 'intro-buildoptions.json'), encoding='utf-8') as boptions:
         meson_command += ['-D{name}={value}'.format(**o) for o in json.load(boptions)
                           if o['name'] not in ['backend', 'install_umask', 'buildtype']]
     meson_command += extra_meson_args
diff --git a/mesonbuild/mesondata.py b/mesonbuild/mesondata.py
index b9a4c10..43b7bde 100644
--- a/mesonbuild/mesondata.py
+++ b/mesonbuild/mesondata.py
@@ -361,7 +361,7 @@ class DataFile:
 
     def write_once(self, path: Path) -> None:
         if not path.exists():
-            path.write_text(self.data)
+            path.write_text(self.data, encoding='utf-8')
 
     def write_to_private(self, env: 'Environment') -> Path:
         out_file = Path(env.scratch_dir) / 'data' / self.path.name
diff --git a/mesonbuild/mesonlib/posix.py b/mesonbuild/mesonlib/posix.py
index 1d8ba8c..67f9a44 100644
--- a/mesonbuild/mesonlib/posix.py
+++ b/mesonbuild/mesonlib/posix.py
@@ -27,7 +27,7 @@ __all__ = ['BuildDirLock']
 class BuildDirLock(BuildDirLockBase):
 
     def __enter__(self) -> None:
-        self.lockfile = open(self.lockfilename, 'w')
+        self.lockfile = open(self.lockfilename, 'w', encoding='utf-8')
         try:
             fcntl.flock(self.lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
         except (BlockingIOError, PermissionError):
diff --git a/mesonbuild/mesonlib/universal.py b/mesonbuild/mesonlib/universal.py
index 0ed99a5..c500e15 100644
--- a/mesonbuild/mesonlib/universal.py
+++ b/mesonbuild/mesonlib/universal.py
@@ -1359,7 +1359,7 @@ def expand_arguments(args: T.Iterable[str]) -> T.Optional[T.List[str]]:
 
         args_file = arg[1:]
         try:
-            with open(args_file) as f:
+            with open(args_file, encoding='utf-8') as f:
                 extended_args = f.read().split()
             expended_args += extended_args
         except Exception as e:
@@ -1854,11 +1854,11 @@ def get_wine_shortpath(winecmd: T.List[str], wine_paths: T.Sequence[str]) -> str
     wine_paths = list(OrderedSet(wine_paths))
 
     getShortPathScript = '%s.bat' % str(uuid.uuid4()).lower()[:5]
-    with open(getShortPathScript, mode='w') as f:
+    with open(getShortPathScript, mode='w', encoding='utf-8') as f:
         f.write("@ECHO OFF\nfor %%x in (%*) do (\n echo|set /p=;%~sx\n)\n")
         f.flush()
     try:
-        with open(os.devnull, 'w') as stderr:
+        with open(os.devnull, 'w', encoding='utf-8') as stderr:
             wine_path = subprocess.check_output(
                 winecmd +
                 ['cmd', '/C', getShortPathScript] + wine_paths,
diff --git a/mesonbuild/mesonlib/win32.py b/mesonbuild/mesonlib/win32.py
index 0919ef7..bc0caec 100644
--- a/mesonbuild/mesonlib/win32.py
+++ b/mesonbuild/mesonlib/win32.py
@@ -27,7 +27,7 @@ __all__ = ['BuildDirLock']
 class BuildDirLock(BuildDirLockBase):
 
     def __enter__(self) -> None:
-        self.lockfile = open(self.lockfilename, 'w')
+        self.lockfile = open(self.lockfilename, 'w', encoding='utf-8')
         try:
             msvcrt.locking(self.lockfile.fileno(), msvcrt.LK_NBLCK, 1)
         except (BlockingIOError, PermissionError):
diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index a3fd27d..86ae973 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -100,7 +100,7 @@ def setup_vsenv() -> None:
 
     bat_separator = '---SPLIT---'
     bat_contents = bat_template.format(bat_path, bat_separator)
-    bat_file.write_text(bat_contents)
+    bat_file.write_text(bat_contents, encoding='utf-8')
     try:
         bat_output = subprocess.check_output(str(bat_file), universal_newlines=True)
     finally:
diff --git a/mesonbuild/minstall.py b/mesonbuild/minstall.py
index 7011c42..b631d4a 100644
--- a/mesonbuild/minstall.py
+++ b/mesonbuild/minstall.py
@@ -708,7 +708,7 @@ def run(opts: 'ArgumentType') -> int:
         if not rebuild_all(opts.wd):
             sys.exit(-1)
     os.chdir(opts.wd)
-    with open(os.path.join(log_dir, 'install-log.txt'), 'w') as lf:
+    with open(os.path.join(log_dir, 'install-log.txt'), 'w', encoding='utf-8') as lf:
         installer = Installer(opts, lf)
         append_to_log(lf, '# List of files installed by Meson')
         append_to_log(lf, '# Does not contain files installed by custom scripts.')
diff --git a/mesonbuild/mintro.py b/mesonbuild/mintro.py
index 430b2f1..73790a5 100644
--- a/mesonbuild/mintro.py
+++ b/mesonbuild/mintro.py
@@ -394,7 +394,7 @@ def get_info_file(infodir: str, kind: T.Optional[str] = None) -> str:
                         'meson-info.json' if not kind else f'intro-{kind}.json')
 
 def load_info_file(infodir: str, kind: T.Optional[str] = None) -> T.Any:
-    with open(get_info_file(infodir, kind)) as fp:
+    with open(get_info_file(infodir, kind), encoding='utf-8') as fp:
         return json.load(fp)
 
 def run(options: argparse.Namespace) -> int:
@@ -464,7 +464,7 @@ def write_intro_info(intro_info: T.Sequence[T.Tuple[str, T.Union[dict, T.List[T.
     for i in intro_info:
         out_file = os.path.join(info_dir, 'intro-{}.json'.format(i[0]))
         tmp_file = os.path.join(info_dir, 'tmp_dump.json')
-        with open(tmp_file, 'w') as fp:
+        with open(tmp_file, 'w', encoding='utf-8') as fp:
             json.dump(i[1], fp)
             fp.flush() # Not sure if this is needed
         os.replace(tmp_file, out_file)
@@ -535,7 +535,7 @@ def write_meson_info_file(builddata: build.Build, errors: list, build_files_upda
 
     # Write the data to disc
     tmp_file = os.path.join(info_dir, 'tmp_dump.json')
-    with open(tmp_file, 'w') as fp:
+    with open(tmp_file, 'w', encoding='utf-8') as fp:
         json.dump(info_data, fp)
         fp.flush()
     os.replace(tmp_file, info_file)
diff --git a/mesonbuild/mlog.py b/mesonbuild/mlog.py
index 5c76677..314e1b7 100644
--- a/mesonbuild/mlog.py
+++ b/mesonbuild/mlog.py
@@ -100,7 +100,7 @@ def set_verbose() -> None:
 def initialize(logdir: str, fatal_warnings: bool = False) -> None:
     global log_dir, log_file, log_fatal_warnings
     log_dir = logdir
-    log_file = open(os.path.join(logdir, log_fname), 'w', encoding='utf8')
+    log_file = open(os.path.join(logdir, log_fname), 'w', encoding='utf-8')
     log_fatal_warnings = fatal_warnings
 
 def set_timestamp_start(start: float) -> None:
diff --git a/mesonbuild/modules/cmake.py b/mesonbuild/modules/cmake.py
index cb37edc..c390b01 100644
--- a/mesonbuild/modules/cmake.py
+++ b/mesonbuild/modules/cmake.py
@@ -298,7 +298,7 @@ class CmakeModule(ExtensionModule):
         package_init += PACKAGE_INIT_SET_AND_CHECK
 
         try:
-            with open(infile) as fin:
+            with open(infile, encoding='utf-8') as fin:
                 data = fin.readlines()
         except Exception as e:
             raise mesonlib.MesonException('Could not read input file {}: {}'.format(infile, str(e)))
diff --git a/mesonbuild/modules/dlang.py b/mesonbuild/modules/dlang.py
index e2a55b6..b6efc86 100644
--- a/mesonbuild/modules/dlang.py
+++ b/mesonbuild/modules/dlang.py
@@ -70,7 +70,7 @@ class DlangModule(ExtensionModule):
 
         config_path = os.path.join(args[1], 'dub.json')
         if os.path.exists(config_path):
-            with open(config_path, encoding='utf8') as ofile:
+            with open(config_path, encoding='utf-8') as ofile:
                 try:
                     config = json.load(ofile)
                 except ValueError:
@@ -108,7 +108,7 @@ class DlangModule(ExtensionModule):
             else:
                 config[key] = value
 
-        with open(config_path, 'w', encoding='utf8') as ofile:
+        with open(config_path, 'w', encoding='utf-8') as ofile:
             ofile.write(json.dumps(config, indent=4, ensure_ascii=False))
 
     def _call_dubbin(self, args, env=None):
diff --git a/mesonbuild/modules/gnome.py b/mesonbuild/modules/gnome.py
index efd1f00..1b68f6c 100644
--- a/mesonbuild/modules/gnome.py
+++ b/mesonbuild/modules/gnome.py
@@ -1713,7 +1713,7 @@ G_END_DECLS'''
     def _generate_deps(self, state, library, packages, install_dir):
         outdir = state.environment.scratch_dir
         fname = os.path.join(outdir, library + '.deps')
-        with open(fname, 'w') as ofile:
+        with open(fname, 'w', encoding='utf-8') as ofile:
             for package in packages:
                 ofile.write(package + '\n')
         return build.Data([mesonlib.File(True, outdir, fname)], install_dir, None, state.subproject)
diff --git a/mesonbuild/modules/hotdoc.py b/mesonbuild/modules/hotdoc.py
index 26026fb..4dccd06 100644
--- a/mesonbuild/modules/hotdoc.py
+++ b/mesonbuild/modules/hotdoc.py
@@ -310,7 +310,7 @@ class HotdocTargetBuilder:
         hotdoc_config_name = fullname + '.json'
         hotdoc_config_path = os.path.join(
             self.builddir, self.subdir, hotdoc_config_name)
-        with open(hotdoc_config_path, 'w') as f:
+        with open(hotdoc_config_path, 'w', encoding='utf-8') as f:
             f.write('{}')
 
         self.cmd += ['--conf-file', hotdoc_config_path]
diff --git a/mesonbuild/modules/keyval.py b/mesonbuild/modules/keyval.py
index d637ac0..b2d54db 100644
--- a/mesonbuild/modules/keyval.py
+++ b/mesonbuild/modules/keyval.py
@@ -32,7 +32,7 @@ class KeyvalModule(ExtensionModule):
     def _load_file(self, path_to_config):
         result = dict()
         try:
-            with open(path_to_config) as f:
+            with open(path_to_config, encoding='utf-8') as f:
                 for line in f:
                     if '#' in line:
                         comment_idx = line.index('#')
diff --git a/mesonbuild/modules/rpm.py b/mesonbuild/modules/rpm.py
index 704e82b..1fae144 100644
--- a/mesonbuild/modules/rpm.py
+++ b/mesonbuild/modules/rpm.py
@@ -77,7 +77,7 @@ class RPMModule(ExtensionModule):
 
         filename = os.path.join(state.environment.get_build_dir(),
                                 '%s.spec' % proj)
-        with open(filename, 'w+') as fn:
+        with open(filename, 'w+', encoding='utf-8') as fn:
             fn.write('Name: %s\n' % proj)
             fn.write('Version: # FIXME\n')
             fn.write('Release: 1%{?dist}\n')
diff --git a/mesonbuild/modules/unstable_external_project.py b/mesonbuild/modules/unstable_external_project.py
index e997f6a..4f8ac56 100644
--- a/mesonbuild/modules/unstable_external_project.py
+++ b/mesonbuild/modules/unstable_external_project.py
@@ -162,7 +162,7 @@ class ExternalProject(ModuleObject):
         log_filename = Path(mlog.log_dir, f'{self.name}-{step}.log')
         output = None
         if not self.verbose:
-            output = open(log_filename, 'w')
+            output = open(log_filename, 'w', encoding='utf-8')
             output.write(m + '\n')
             output.flush()
         else:
diff --git a/mesonbuild/msetup.py b/mesonbuild/msetup.py
index b348948..9ed2981 100644
--- a/mesonbuild/msetup.py
+++ b/mesonbuild/msetup.py
@@ -148,9 +148,9 @@ class MesonApp:
     def add_vcs_ignore_files(self, build_dir: str) -> None:
         if os.listdir(build_dir):
             return
-        with open(os.path.join(build_dir, '.gitignore'), 'w') as ofile:
+        with open(os.path.join(build_dir, '.gitignore'), 'w', encoding='utf-8') as ofile:
             ofile.write(git_ignore_file)
-        with open(os.path.join(build_dir, '.hgignore'), 'w') as ofile:
+        with open(os.path.join(build_dir, '.hgignore'), 'w', encoding='utf-8') as ofile:
             ofile.write(hg_ignore_file)
 
     def validate_dirs(self, dir1: str, dir2: str, reconfigure: bool, wipe: bool) -> T.Tuple[str, str]:
diff --git a/mesonbuild/mtest.py b/mesonbuild/mtest.py
index e54740e..826619f 100644
--- a/mesonbuild/mtest.py
+++ b/mesonbuild/mtest.py
@@ -467,7 +467,7 @@ class TestLogger:
 class TestFileLogger(TestLogger):
     def __init__(self, filename: str, errors: str = 'replace') -> None:
         self.filename = filename
-        self.file = open(filename, 'w', encoding='utf8', errors=errors)
+        self.file = open(filename, 'w', encoding='utf-8', errors=errors)
 
     def close(self) -> None:
         if self.file:
diff --git a/mesonbuild/optinterpreter.py b/mesonbuild/optinterpreter.py
index 6043691..72bf865 100644
--- a/mesonbuild/optinterpreter.py
+++ b/mesonbuild/optinterpreter.py
@@ -142,7 +142,7 @@ class OptionInterpreter:
 
     def process(self, option_file: str) -> None:
         try:
-            with open(option_file, encoding='utf8') as f:
+            with open(option_file, encoding='utf-8') as f:
                 ast = mparser.Parser(f.read(), option_file).parse()
         except mesonlib.MesonException as me:
             me.file = option_file
diff --git a/mesonbuild/programs.py b/mesonbuild/programs.py
index bb14f96..ffd177f 100644
--- a/mesonbuild/programs.py
+++ b/mesonbuild/programs.py
@@ -176,7 +176,7 @@ class ExternalProgram(mesonlib.HoldableObject):
         or if we're on Windows (which does not understand shebangs).
         """
         try:
-            with open(script) as f:
+            with open(script, encoding='utf-8') as f:
                 first_line = f.readline().strip()
             if first_line.startswith('#!'):
                 # In a shebang, everything before the first space is assumed to
diff --git a/mesonbuild/rewriter.py b/mesonbuild/rewriter.py
index ddd712f..3f661a4 100644
--- a/mesonbuild/rewriter.py
+++ b/mesonbuild/rewriter.py
@@ -818,9 +818,9 @@ class Rewriter:
             fdata = ''
             # Create an empty file if it does not exist
             if not os.path.exists(fpath):
-                with open(fpath, 'w'):
+                with open(fpath, 'w', encoding='utf-8'):
                     pass
-            with open(fpath) as fp:
+            with open(fpath, encoding='utf-8') as fp:
                 fdata = fp.read()
 
             # Generate line offsets numbers
@@ -871,7 +871,7 @@ class Rewriter:
         # Write the files back
         for key, val in files.items():
             mlog.log('Rewriting', mlog.yellow(key))
-            with open(val['path'], 'w') as fp:
+            with open(val['path'], 'w', encoding='utf-8') as fp:
                 fp.write(val['raw'])
 
 target_operation_map = {
@@ -923,7 +923,7 @@ def generate_def_opts(options) -> T.List[dict]:
 
 def generate_cmd(options) -> T.List[dict]:
     if os.path.exists(options.json):
-        with open(options.json) as fp:
+        with open(options.json, encoding='utf-8') as fp:
             return json.load(fp)
     else:
         return json.loads(options.json)
diff --git a/mesonbuild/scripts/coverage.py b/mesonbuild/scripts/coverage.py
index f8a4924..b60d5d1 100644
--- a/mesonbuild/scripts/coverage.py
+++ b/mesonbuild/scripts/coverage.py
@@ -68,11 +68,11 @@ def coverage(outputs: T.List[str], source_root: str, subproject_root: str, build
                 # Create a shim to allow using llvm-cov as a gcov tool.
                 if mesonlib.is_windows():
                     llvm_cov_shim_path = os.path.join(log_dir, 'llvm-cov.bat')
-                    with open(llvm_cov_shim_path, 'w') as llvm_cov_bat:
+                    with open(llvm_cov_shim_path, 'w', encoding='utf-8') as llvm_cov_bat:
                         llvm_cov_bat.write(f'@"{llvm_cov_exe}" gcov %*')
                 else:
                     llvm_cov_shim_path = os.path.join(log_dir, 'llvm-cov.sh')
-                    with open(llvm_cov_shim_path, 'w') as llvm_cov_sh:
+                    with open(llvm_cov_shim_path, 'w', encoding='utf-8') as llvm_cov_sh:
                         llvm_cov_sh.write(f'#!/usr/bin/env sh\nexec "{llvm_cov_exe}" gcov $@')
                     os.chmod(llvm_cov_shim_path, os.stat(llvm_cov_shim_path).st_mode | stat.S_IEXEC)
                 gcov_tool_args = ['--gcov-tool', llvm_cov_shim_path]
diff --git a/mesonbuild/scripts/depfixer.py b/mesonbuild/scripts/depfixer.py
index c215749..52c7ba9 100644
--- a/mesonbuild/scripts/depfixer.py
+++ b/mesonbuild/scripts/depfixer.py
@@ -468,7 +468,7 @@ def fix_darwin(fname: str, new_rpath: str, final_path: str, install_name_mapping
 
 def fix_jar(fname: str) -> None:
     subprocess.check_call(['jar', 'xfv', fname, 'META-INF/MANIFEST.MF'])
-    with open('META-INF/MANIFEST.MF', 'r+') as f:
+    with open('META-INF/MANIFEST.MF', 'r+', encoding='utf-8') as f:
         lines = f.readlines()
         f.seek(0)
         for line in lines:
diff --git a/mesonbuild/scripts/depscan.py b/mesonbuild/scripts/depscan.py
index 207bbc6..9fc435b 100644
--- a/mesonbuild/scripts/depscan.py
+++ b/mesonbuild/scripts/depscan.py
@@ -57,7 +57,7 @@ class DependencyScanner:
     def scan_fortran_file(self, fname: str) -> None:
         fpath = pathlib.Path(fname)
         modules_in_this_file = set()
-        for line in fpath.read_text().split('\n'):
+        for line in fpath.read_text(encoding='utf-8').split('\n'):
             import_match = FORTRAN_USE_RE.match(line)
             export_match = FORTRAN_MODULE_RE.match(line)
             submodule_export_match = FORTRAN_SUBMOD_RE.match(line)
@@ -108,7 +108,7 @@ class DependencyScanner:
 
     def scan_cpp_file(self, fname: str) -> None:
         fpath = pathlib.Path(fname)
-        for line in fpath.read_text().split('\n'):
+        for line in fpath.read_text(encoding='utf-8').split('\n'):
             import_match = CPP_IMPORT_RE.match(line)
             export_match = CPP_EXPORT_RE.match(line)
             if import_match:
@@ -150,7 +150,7 @@ class DependencyScanner:
     def scan(self) -> int:
         for s in self.sources:
             self.scan_file(s)
-        with open(self.outfile, 'w') as ofile:
+        with open(self.outfile, 'w', encoding='utf-8') as ofile:
             ofile.write('ninja_dyndep_version = 1\n')
             for src in self.sources:
                 objfilename = self.objname_for(src)
diff --git a/mesonbuild/scripts/externalproject.py b/mesonbuild/scripts/externalproject.py
index 657ef2f..a8e3bfe 100644
--- a/mesonbuild/scripts/externalproject.py
+++ b/mesonbuild/scripts/externalproject.py
@@ -34,7 +34,7 @@ class ExternalProject:
         self.make = options.make
 
     def write_depfile(self) -> None:
-        with open(self.depfile, 'w') as f:
+        with open(self.depfile, 'w', encoding='utf-8') as f:
             f.write(f'{self.stampfile}: \\\n')
             for dirpath, dirnames, filenames in os.walk(self.src_dir):
                 dirnames[:] = [d for d in dirnames if not d.startswith('.')]
@@ -45,7 +45,7 @@ class ExternalProject:
                     f.write('  {} \\\n'.format(path.as_posix().replace(' ', '\\ ')))
 
     def write_stampfile(self) -> None:
-        with open(self.stampfile, 'w') as f:
+        with open(self.stampfile, 'w', encoding='utf-8') as f:
             pass
 
     def gnu_make(self) -> bool:
@@ -78,7 +78,7 @@ class ExternalProject:
         log_filename = Path(self.log_dir, f'{self.name}-{step}.log')
         output = None
         if not self.verbose:
-            output = open(log_filename, 'w')
+            output = open(log_filename, 'w', encoding='utf-8')
             output.write(m + '\n')
             output.flush()
         else:
diff --git a/mesonbuild/scripts/gettext.py b/mesonbuild/scripts/gettext.py
index 92b55d3..b1ce6af 100644
--- a/mesonbuild/scripts/gettext.py
+++ b/mesonbuild/scripts/gettext.py
@@ -34,7 +34,7 @@ def read_linguas(src_sub: str) -> T.List[str]:
     linguas = os.path.join(src_sub, 'LINGUAS')
     try:
         langs = []
-        with open(linguas) as f:
+        with open(linguas, encoding='utf-8') as f:
             for line in f:
                 line = line.strip()
                 if line and not line.startswith('#'):
diff --git a/mesonbuild/scripts/symbolextractor.py b/mesonbuild/scripts/symbolextractor.py
index 728d5e2..17501e2 100644
--- a/mesonbuild/scripts/symbolextractor.py
+++ b/mesonbuild/scripts/symbolextractor.py
@@ -38,18 +38,18 @@ RELINKING_WARNING = 'Relinking will always happen on source changes.'
 
 def dummy_syms(outfilename: str) -> None:
     """Just touch it so relinking happens always."""
-    with open(outfilename, 'w'):
+    with open(outfilename, 'w', encoding='utf-8'):
         pass
 
 def write_if_changed(text: str, outfilename: str) -> None:
     try:
-        with open(outfilename) as f:
+        with open(outfilename, encoding='utf-8') as f:
             oldtext = f.read()
         if text == oldtext:
             return
     except FileNotFoundError:
         pass
-    with open(outfilename, 'w') as f:
+    with open(outfilename, 'w', encoding='utf-8') as f:
         f.write(text)
 
 def print_tool_warning(tools: T.List[str], msg: str, stderr: T.Optional[str] = None) -> None:
@@ -61,7 +61,7 @@ def print_tool_warning(tools: T.List[str], msg: str, stderr: T.Optional[str] = N
         m += '\n' + stderr
     mlog.warning(m)
     # Write it out so we don't warn again
-    with open(TOOL_WARNING_FILE, 'w'):
+    with open(TOOL_WARNING_FILE, 'w', encoding='utf-8'):
         pass
 
 def get_tool(name: str) -> T.List[str]:
@@ -309,7 +309,7 @@ def gen_symbols(libfilename: str, impfilename: str, outfilename: str, cross_host
             mlog.warning('Symbol extracting has not been implemented for this '
                          'platform. ' + RELINKING_WARNING)
             # Write it out so we don't warn again
-            with open(TOOL_WARNING_FILE, 'w'):
+            with open(TOOL_WARNING_FILE, 'w', encoding='utf-8'):
                 pass
         dummy_syms(outfilename)
 
diff --git a/mesonbuild/scripts/uninstall.py b/mesonbuild/scripts/uninstall.py
index 8db04dd..f08490f 100644
--- a/mesonbuild/scripts/uninstall.py
+++ b/mesonbuild/scripts/uninstall.py
@@ -20,7 +20,7 @@ logfile = 'meson-logs/install-log.txt'
 def do_uninstall(log: str) -> None:
     failures = 0
     successes = 0
-    for line in open(log):
+    for line in open(log, encoding='utf-8'):
         if line.startswith('#'):
             continue
         fname = line.strip()
diff --git a/mesonbuild/scripts/vcstagger.py b/mesonbuild/scripts/vcstagger.py
index 64985f6..18cf5f7 100644
--- a/mesonbuild/scripts/vcstagger.py
+++ b/mesonbuild/scripts/vcstagger.py
@@ -22,15 +22,15 @@ def config_vcs_tag(infile: str, outfile: str, fallback: str, source_dir: str, re
     except Exception:
         new_string = fallback
 
-    with open(infile, encoding='utf8') as f:
+    with open(infile, encoding='utf-8') as f:
         new_data = f.read().replace(replace_string, new_string)
     if os.path.exists(outfile):
-        with open(outfile, encoding='utf8') as f:
+        with open(outfile, encoding='utf-8') as f:
             needs_update = (f.read() != new_data)
     else:
         needs_update = True
     if needs_update:
-        with open(outfile, 'w', encoding='utf8') as f:
+        with open(outfile, 'w', encoding='utf-8') as f:
             f.write(new_data)
 
 
diff --git a/mesonbuild/templates/cpptemplates.py b/mesonbuild/templates/cpptemplates.py
index 2d28d3a..61c2737 100644
--- a/mesonbuild/templates/cpptemplates.py
+++ b/mesonbuild/templates/cpptemplates.py
@@ -149,11 +149,12 @@ class CppProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.cpp'
-        open(source_name, 'w').write(hello_cpp_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_cpp_meson_template.format(project_name=self.name,
-                                                                       exe_name=lowercase_token,
-                                                                       source_name=source_name,
-                                                                       version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_cpp_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_cpp_meson_template.format(project_name=self.name,
+                                            exe_name=lowercase_token,
+                                            source_name=source_name,
+                                            version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -178,7 +179,7 @@ class CppProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_hpp_name, 'w').write(lib_hpp_template.format(**kwargs))
-        open(lib_cpp_name, 'w').write(lib_cpp_template.format(**kwargs))
-        open(test_cpp_name, 'w').write(lib_cpp_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_cpp_meson_template.format(**kwargs))
+        open(lib_hpp_name, 'w', encoding='utf-8').write(lib_hpp_template.format(**kwargs))
+        open(lib_cpp_name, 'w', encoding='utf-8').write(lib_cpp_template.format(**kwargs))
+        open(test_cpp_name, 'w', encoding='utf-8').write(lib_cpp_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_cpp_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/cstemplates.py b/mesonbuild/templates/cstemplates.py
index 8524c97..bad7984 100644
--- a/mesonbuild/templates/cstemplates.py
+++ b/mesonbuild/templates/cstemplates.py
@@ -100,12 +100,14 @@ class CSharpProject(SampleImpl):
         uppercase_token = lowercase_token.upper()
         class_name = uppercase_token[0] + lowercase_token[1:]
         source_name = uppercase_token[0] + lowercase_token[1:] + '.cs'
-        open(source_name, 'w').write(hello_cs_template.format(project_name=self.name,
-                                                              class_name=class_name))
-        open('meson.build', 'w').write(hello_cs_meson_template.format(project_name=self.name,
-                                                                      exe_name=self.name,
-                                                                      source_name=source_name,
-                                                                      version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(
+            hello_cs_template.format(project_name=self.name,
+                                     class_name=class_name))
+        open('meson.build', 'w', encoding='utf-8').write(
+          hello_cs_meson_template.format(project_name=self.name,
+                                         exe_name=self.name,
+                                         source_name=source_name,
+                                         version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -127,6 +129,6 @@ class CSharpProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_cs_name, 'w').write(lib_cs_template.format(**kwargs))
-        open(test_cs_name, 'w').write(lib_cs_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_cs_meson_template.format(**kwargs))
+        open(lib_cs_name, 'w', encoding='utf-8').write(lib_cs_template.format(**kwargs))
+        open(test_cs_name, 'w', encoding='utf-8').write(lib_cs_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_cs_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/ctemplates.py b/mesonbuild/templates/ctemplates.py
index 440731c..9b651bc 100644
--- a/mesonbuild/templates/ctemplates.py
+++ b/mesonbuild/templates/ctemplates.py
@@ -132,11 +132,12 @@ class CProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.c'
-        open(source_name, 'w').write(hello_c_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_c_meson_template.format(project_name=self.name,
-                                                                     exe_name=lowercase_token,
-                                                                     source_name=source_name,
-                                                                     version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_c_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_c_meson_template.format(project_name=self.name,
+                                          exe_name=lowercase_token,
+                                          source_name=source_name,
+                                          version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -159,7 +160,7 @@ class CProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_h_name, 'w').write(lib_h_template.format(**kwargs))
-        open(lib_c_name, 'w').write(lib_c_template.format(**kwargs))
-        open(test_c_name, 'w').write(lib_c_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_c_meson_template.format(**kwargs))
+        open(lib_h_name, 'w', encoding='utf-8').write(lib_h_template.format(**kwargs))
+        open(lib_c_name, 'w', encoding='utf-8').write(lib_c_template.format(**kwargs))
+        open(test_c_name, 'w', encoding='utf-8').write(lib_c_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_c_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/cudatemplates.py b/mesonbuild/templates/cudatemplates.py
index 4fa9a2b..919db21 100644
--- a/mesonbuild/templates/cudatemplates.py
+++ b/mesonbuild/templates/cudatemplates.py
@@ -149,11 +149,12 @@ class CudaProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.cu'
-        open(source_name, 'w').write(hello_cuda_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_cuda_meson_template.format(project_name=self.name,
-                                                                        exe_name=lowercase_token,
-                                                                        source_name=source_name,
-                                                                        version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_cuda_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_cuda_meson_template.format(project_name=self.name,
+                                             exe_name=lowercase_token,
+                                             source_name=source_name,
+                                             version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -178,7 +179,7 @@ class CudaProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_h_name, 'w').write(lib_h_template.format(**kwargs))
-        open(lib_cuda_name, 'w').write(lib_cuda_template.format(**kwargs))
-        open(test_cuda_name, 'w').write(lib_cuda_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_cuda_meson_template.format(**kwargs))
+        open(lib_h_name, 'w', encoding='utf-8').write(lib_h_template.format(**kwargs))
+        open(lib_cuda_name, 'w', encoding='utf-8').write(lib_cuda_template.format(**kwargs))
+        open(test_cuda_name, 'w', encoding='utf-8').write(lib_cuda_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_cuda_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/dlangtemplates.py b/mesonbuild/templates/dlangtemplates.py
index 4aacda8..3d939d8 100644
--- a/mesonbuild/templates/dlangtemplates.py
+++ b/mesonbuild/templates/dlangtemplates.py
@@ -110,11 +110,12 @@ class DlangProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.d'
-        open(source_name, 'w').write(hello_d_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_d_meson_template.format(project_name=self.name,
-                                                                     exe_name=lowercase_token,
-                                                                     source_name=source_name,
-                                                                     version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_d_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_d_meson_template.format(project_name=self.name,
+                                          exe_name=lowercase_token,
+                                          source_name=source_name,
+                                          version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -137,6 +138,6 @@ class DlangProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_d_name, 'w').write(lib_d_template.format(**kwargs))
-        open(test_d_name, 'w').write(lib_d_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_d_meson_template.format(**kwargs))
+        open(lib_d_name, 'w', encoding='utf-8').write(lib_d_template.format(**kwargs))
+        open(test_d_name, 'w', encoding='utf-8').write(lib_d_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_d_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/fortrantemplates.py b/mesonbuild/templates/fortrantemplates.py
index f4cae66..8fc1bca 100644
--- a/mesonbuild/templates/fortrantemplates.py
+++ b/mesonbuild/templates/fortrantemplates.py
@@ -109,11 +109,12 @@ class FortranProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.f90'
-        open(source_name, 'w').write(hello_fortran_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_fortran_meson_template.format(project_name=self.name,
-                                                                           exe_name=lowercase_token,
-                                                                           source_name=source_name,
-                                                                           version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_fortran_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_fortran_meson_template.format(project_name=self.name,
+                                                exe_name=lowercase_token,
+                                                source_name=source_name,
+                                                version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -134,6 +135,6 @@ class FortranProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_fortran_name, 'w').write(lib_fortran_template.format(**kwargs))
-        open(test_fortran_name, 'w').write(lib_fortran_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_fortran_meson_template.format(**kwargs))
+        open(lib_fortran_name, 'w', encoding='utf-8').write(lib_fortran_template.format(**kwargs))
+        open(test_fortran_name, 'w', encoding='utf-8').write(lib_fortran_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_fortran_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/javatemplates.py b/mesonbuild/templates/javatemplates.py
index 9c64743..e432961 100644
--- a/mesonbuild/templates/javatemplates.py
+++ b/mesonbuild/templates/javatemplates.py
@@ -104,12 +104,14 @@ class JavaProject(SampleImpl):
         uppercase_token = lowercase_token.upper()
         class_name = uppercase_token[0] + lowercase_token[1:]
         source_name = uppercase_token[0] + lowercase_token[1:] + '.java'
-        open(source_name, 'w').write(hello_java_template.format(project_name=self.name,
-                                                                class_name=class_name))
-        open('meson.build', 'w').write(hello_java_meson_template.format(project_name=self.name,
-                                                                        exe_name=class_name,
-                                                                        source_name=source_name,
-                                                                        version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(
+            hello_java_template.format(project_name=self.name,
+                                       class_name=class_name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_java_meson_template.format(project_name=self.name,
+                                             exe_name=class_name,
+                                             source_name=source_name,
+                                             version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -129,6 +131,6 @@ class JavaProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_java_name, 'w').write(lib_java_template.format(**kwargs))
-        open(test_java_name, 'w').write(lib_java_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_java_meson_template.format(**kwargs))
+        open(lib_java_name, 'w', encoding='utf-8').write(lib_java_template.format(**kwargs))
+        open(test_java_name, 'w', encoding='utf-8').write(lib_java_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_java_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/mesontemplates.py b/mesonbuild/templates/mesontemplates.py
index 4c4d66f..a29ac6f 100644
--- a/mesonbuild/templates/mesontemplates.py
+++ b/mesonbuild/templates/mesontemplates.py
@@ -71,5 +71,5 @@ def create_meson_build(options: argparse.Namespace) -> None:
                                             sourcespec=sourcespec,
                                             depspec=depspec,
                                             default_options=formatted_default_options)
-    open('meson.build', 'w').write(content)
+    open('meson.build', 'w', encoding='utf-8').write(content)
     print('Generated meson.build file:\n\n' + content)
diff --git a/mesonbuild/templates/objcpptemplates.py b/mesonbuild/templates/objcpptemplates.py
index f4f4b51..4f61d6c 100644
--- a/mesonbuild/templates/objcpptemplates.py
+++ b/mesonbuild/templates/objcpptemplates.py
@@ -132,11 +132,12 @@ class ObjCppProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.mm'
-        open(source_name, 'w').write(hello_objcpp_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_objcpp_meson_template.format(project_name=self.name,
-                                                                          exe_name=lowercase_token,
-                                                                          source_name=source_name,
-                                                                          version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_objcpp_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_objcpp_meson_template.format(project_name=self.name,
+                                               exe_name=lowercase_token,
+                                               source_name=source_name,
+                                               version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -159,8 +160,8 @@ class ObjCppProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_h_name, 'w').write(lib_h_template.format(**kwargs))
-        open(lib_objcpp_name, 'w').write(lib_objcpp_template.format(**kwargs))
-        open(test_objcpp_name, 'w').write(lib_objcpp_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_objcpp_meson_template.format(**kwargs))
+        open(lib_h_name, 'w', encoding='utf-8').write(lib_h_template.format(**kwargs))
+        open(lib_objcpp_name, 'w', encoding='utf-8').write(lib_objcpp_template.format(**kwargs))
+        open(test_objcpp_name, 'w', encoding='utf-8').write(lib_objcpp_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_objcpp_meson_template.format(**kwargs))
 
diff --git a/mesonbuild/templates/objctemplates.py b/mesonbuild/templates/objctemplates.py
index 4243024..dac638d 100644
--- a/mesonbuild/templates/objctemplates.py
+++ b/mesonbuild/templates/objctemplates.py
@@ -132,11 +132,12 @@ class ObjCProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.m'
-        open(source_name, 'w').write(hello_objc_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_objc_meson_template.format(project_name=self.name,
-                                                                        exe_name=lowercase_token,
-                                                                        source_name=source_name,
-                                                                        version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_objc_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_objc_meson_template.format(project_name=self.name,
+                                             exe_name=lowercase_token,
+                                             source_name=source_name,
+                                             version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -159,7 +160,7 @@ class ObjCProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_h_name, 'w').write(lib_h_template.format(**kwargs))
-        open(lib_objc_name, 'w').write(lib_objc_template.format(**kwargs))
-        open(test_objc_name, 'w').write(lib_objc_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_objc_meson_template.format(**kwargs))
+        open(lib_h_name, 'w', encoding='utf-8').write(lib_h_template.format(**kwargs))
+        open(lib_objc_name, 'w', encoding='utf-8').write(lib_objc_template.format(**kwargs))
+        open(test_objc_name, 'w', encoding='utf-8').write(lib_objc_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_objc_meson_template.format(**kwargs))
diff --git a/mesonbuild/templates/rusttemplates.py b/mesonbuild/templates/rusttemplates.py
index 6e99586..95a937c 100644
--- a/mesonbuild/templates/rusttemplates.py
+++ b/mesonbuild/templates/rusttemplates.py
@@ -80,11 +80,12 @@ class RustProject(SampleImpl):
     def create_executable(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
         source_name = lowercase_token + '.rs'
-        open(source_name, 'w').write(hello_rust_template.format(project_name=self.name))
-        open('meson.build', 'w').write(hello_rust_meson_template.format(project_name=self.name,
-                                                                        exe_name=lowercase_token,
-                                                                        source_name=source_name,
-                                                                        version=self.version))
+        open(source_name, 'w', encoding='utf-8').write(hello_rust_template.format(project_name=self.name))
+        open('meson.build', 'w', encoding='utf-8').write(
+            hello_rust_meson_template.format(project_name=self.name,
+                                             exe_name=lowercase_token,
+                                             source_name=source_name,
+                                             version=self.version))
 
     def create_library(self) -> None:
         lowercase_token = re.sub(r'[^a-z0-9]', '_', self.name.lower())
@@ -107,6 +108,6 @@ class RustProject(SampleImpl):
                   'test_name': lowercase_token,
                   'version': self.version,
                   }
-        open(lib_rs_name, 'w').write(lib_rust_template.format(**kwargs))
-        open(test_rs_name, 'w').write(lib_rust_test_template.format(**kwargs))
-        open('meson.build', 'w').write(lib_rust_meson_template.format(**kwargs))
+        open(lib_rs_name, 'w', encoding='utf-8').write(lib_rust_template.format(**kwargs))
+        open(test_rs_name, 'w', encoding='utf-8').write(lib_rust_test_template.format(**kwargs))
+        open('meson.build', 'w', encoding='utf-8').write(lib_rust_meson_template.format(**kwargs))
diff --git a/mesonbuild/wrap/wrap.py b/mesonbuild/wrap/wrap.py
index e88d658..4a6583f 100644
--- a/mesonbuild/wrap/wrap.py
+++ b/mesonbuild/wrap/wrap.py
@@ -291,7 +291,7 @@ class Resolver:
                 mlog.log('Using', mlog.bold(rel))
                 # Write a dummy wrap file in main project that redirect to the
                 # wrap we picked.
-                with open(main_fname, 'w') as f:
+                with open(main_fname, 'w', encoding='utf-8') as f:
                     f.write(textwrap.dedent('''\
                         [wrap-redirect]
                         filename = {}
diff --git a/run_cross_test.py b/run_cross_test.py
index 5ce3e55..bafdbb6 100755
--- a/run_cross_test.py
+++ b/run_cross_test.py
@@ -49,7 +49,7 @@ def main():
     options = parser.parse_args()
     cf_path = Path(options.cross_file)
     try:
-        data = json.loads(cf_path.read_text())
+        data = json.loads(cf_path.read_text(encoding='utf-8'))
         real_cf = cf_path.resolve().parent / data['file']
         assert real_cf.exists()
         env = os.environ.copy()
diff --git a/run_meson_command_tests.py b/run_meson_command_tests.py
index c84e415..45096c6 100755
--- a/run_meson_command_tests.py
+++ b/run_meson_command_tests.py
@@ -165,7 +165,7 @@ class CommandTests(unittest.TestCase):
         builddir = str(self.tmpdir / 'build4')
         (bindir / 'meson').rename(bindir / 'meson.real')
         wrapper = (bindir / 'meson')
-        wrapper.open('w').write('#!/bin/sh\n\nmeson.real "$@"')
+        wrapper.write_text('#!/bin/sh\n\nmeson.real "$@"', encoding='utf-8')
         wrapper.chmod(0o755)
         meson_setup = [str(wrapper), 'setup']
         meson_command = meson_setup + self.meson_args
diff --git a/run_mypy.py b/run_mypy.py
index 7ad831d..22a9bdd 100755
--- a/run_mypy.py
+++ b/run_mypy.py
@@ -42,6 +42,7 @@ modules = [
     'mesonbuild/optinterpreter.py',
     'mesonbuild/programs.py',
 
+    'run_encoding_tests.py',
     'run_mypy.py',
     'run_project_tests.py',
     'run_single_test.py',
diff --git a/run_project_tests.py b/run_project_tests.py
index fcd856f..7631b84 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -522,7 +522,7 @@ def run_test_inprocess(testdir: str) -> T.Tuple[int, str, str, str]:
     try:
         returncode_test = mtest.run_with_args(['--no-rebuild'])
         if test_log_fname.exists():
-            test_log = test_log_fname.open(errors='ignore').read()
+            test_log = test_log_fname.open(encoding='utf-8', errors='ignore').read()
         else:
             test_log = ''
         returncode_benchmark = mtest.run_with_args(['--no-rebuild', '--benchmark', '--logbase', 'benchmarklog'])
@@ -736,7 +736,7 @@ def load_test_json(t: TestDef, stdout_mandatory: bool) -> T.List[TestDef]:
     test_def = {}
     test_def_file = t.path / 'test.json'
     if test_def_file.is_file():
-        test_def = json.loads(test_def_file.read_text())
+        test_def = json.loads(test_def_file.read_text(encoding='utf-8'))
 
     # Handle additional environment variables
     env = {}  # type: T.Dict[str, str]
@@ -1022,18 +1022,17 @@ def skip_csharp(backend: Backend) -> bool:
 # on all compilation attempts.
 
 def has_broken_rustc() -> bool:
-    dirname = 'brokenrusttest'
-    if os.path.exists(dirname):
-        mesonlib.windows_proof_rmtree(dirname)
-    os.mkdir(dirname)
-    open(dirname + '/sanity.rs', 'w').write('''fn main() {
-}
-''')
+    dirname = Path('brokenrusttest')
+    if dirname.exists():
+        mesonlib.windows_proof_rmtree(dirname.as_posix())
+    dirname.mkdir()
+    sanity_file = dirname / 'sanity.rs'
+    sanity_file.write_text('fn main() {\n}\n', encoding='utf-8')
     pc = subprocess.run(['rustc', '-o', 'sanity.exe', 'sanity.rs'],
-                        cwd=dirname,
+                        cwd=dirname.as_posix(),
                         stdout = subprocess.DEVNULL,
                         stderr = subprocess.DEVNULL)
-    mesonlib.windows_proof_rmtree(dirname)
+    mesonlib.windows_proof_rmtree(dirname.as_posix())
     return pc.returncode != 0
 
 def should_skip_rust(backend: Backend) -> bool:
diff --git a/run_unittests.py b/run_unittests.py
index 9da20e6..99c56e2 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -809,16 +809,9 @@ class InternalTests(unittest.TestCase):
         if platform != 'openbsd':
             return
         with tempfile.TemporaryDirectory() as tmpdir:
-            with open(os.path.join(tmpdir, 'libfoo.so.6.0'), 'w') as f:
-                f.write('')
-            with open(os.path.join(tmpdir, 'libfoo.so.5.0'), 'w') as f:
-                f.write('')
-            with open(os.path.join(tmpdir, 'libfoo.so.54.0'), 'w') as f:
-                f.write('')
-            with open(os.path.join(tmpdir, 'libfoo.so.66a.0b'), 'w') as f:
-                f.write('')
-            with open(os.path.join(tmpdir, 'libfoo.so.70.0.so.1'), 'w') as f:
-                f.write('')
+            for i in ['libfoo.so.6.0', 'libfoo.so.5.0', 'libfoo.so.54.0', 'libfoo.so.66a.0b', 'libfoo.so.70.0.so.1']:
+                libpath = Path(tmpdir) / i
+                libpath.write_text('', encoding='utf-8')
             found = cc._find_library_real('foo', env, [tmpdir], '', LibType.PREFER_SHARED)
             self.assertEqual(os.path.basename(found[0]), 'libfoo.so.54.0')
 
@@ -876,11 +869,11 @@ class InternalTests(unittest.TestCase):
         '''
         def create_static_lib(name):
             if not is_osx():
-                name.open('w').close()
+                name.open('w', encoding='utf-8').close()
                 return
             src = name.with_suffix('.c')
             out = name.with_suffix('.o')
-            with src.open('w') as f:
+            with src.open('w', encoding='utf-8') as f:
                 f.write('int meson_foobar (void) { return 0; }')
             subprocess.check_call(['clang', '-c', str(src), '-o', str(out)])
             subprocess.check_call(['ar', 'csr', str(name), str(out)])
@@ -1084,7 +1077,7 @@ class InternalTests(unittest.TestCase):
         else:
             self.assertIn('VCINSTALLDIR', os.environ)
             # See https://devblogs.microsoft.com/cppblog/finding-the-visual-c-compiler-tools-in-visual-studio-2017/
-            vctools_ver = (Path(os.environ['VCINSTALLDIR']) / 'Auxiliary' / 'Build' / 'Microsoft.VCToolsVersion.default.txt').read_text()
+            vctools_ver = (Path(os.environ['VCINSTALLDIR']) / 'Auxiliary' / 'Build' / 'Microsoft.VCToolsVersion.default.txt').read_text(encoding='utf-8')
         self.assertTrue(vctools_ver.startswith(toolset_ver),
                         msg=f'{vctools_ver!r} does not start with {toolset_ver!r}')
 
@@ -1292,16 +1285,14 @@ class InternalTests(unittest.TestCase):
                 raise
             raise unittest.SkipTest('Python jsonschema module not found.')
 
-        with Path('data/test.schema.json').open() as f:
-            schema = json.load(f)
+        schema = json.loads(Path('data/test.schema.json').read_text(encoding='utf-8'))
 
         errors = []  # type: T.Tuple[str, Exception]
         for p in Path('test cases').glob('**/test.json'):
-            with p.open() as f:
-                try:
-                    validate(json.load(f), schema=schema)
-                except ValidationError as e:
-                    errors.append((p.resolve(), e))
+            try:
+                validate(json.loads(p.read_text(encoding='utf-8')), schema=schema)
+            except ValidationError as e:
+                errors.append((p.resolve(), e))
 
         for f, e in errors:
             print(f'Failed to validate: "{f}"')
@@ -1731,7 +1722,7 @@ class DataTests(unittest.TestCase):
                 continue
             if f.suffix == '.md':
                 in_code_block = False
-                with f.open() as snippet:
+                with f.open(encoding='utf-8') as snippet:
                     for line in snippet:
                         if line.startswith('    '):
                             continue
@@ -1895,7 +1886,7 @@ class DataTests(unittest.TestCase):
         '''
         env = get_fake_env()
         interp = Interpreter(FakeBuild(env), mock=True)
-        with open('data/syntax-highlighting/vim/syntax/meson.vim') as f:
+        with open('data/syntax-highlighting/vim/syntax/meson.vim', encoding='utf-8') as f:
             res = re.search(r'syn keyword mesonBuiltin(\s+\\\s\w+)+', f.read(), re.MULTILINE)
             defined = set([a.strip() for a in res.group().split('\\')][1:])
             self.assertEqual(defined, set(chain(interp.funcs.keys(), interp.builtin.keys())))
@@ -2163,7 +2154,7 @@ class BasePlatformTests(unittest.TestCase):
         if self.backend is not Backend.ninja:
             raise unittest.SkipTest(f'Compiler db not available with {self.backend.name} backend')
         try:
-            with open(os.path.join(self.builddir, 'compile_commands.json')) as ifile:
+            with open(os.path.join(self.builddir, 'compile_commands.json'), encoding='utf-8') as ifile:
                 contents = json.load(ifile)
         except FileNotFoundError:
             raise unittest.SkipTest('Compiler db not found')
@@ -2182,7 +2173,7 @@ class BasePlatformTests(unittest.TestCase):
         return contents
 
     def get_meson_log(self):
-        with open(os.path.join(self.builddir, 'meson-logs', 'meson-log.txt')) as f:
+        with open(os.path.join(self.builddir, 'meson-logs', 'meson-log.txt'), encoding='utf-8') as f:
             return f.readlines()
 
     def get_meson_log_compiler_checks(self):
@@ -2726,7 +2717,7 @@ class AllPlatformTests(BasePlatformTests):
             expected[name] = 0
         def read_logs():
             # Find logged files and directories
-            with Path(self.builddir, 'meson-logs', 'install-log.txt').open() as f:
+            with Path(self.builddir, 'meson-logs', 'install-log.txt').open(encoding='utf-8') as f:
                 return list(map(lambda l: Path(l.strip()),
                                   filter(lambda l: not l.startswith('#'),
                                          f.readlines())))
@@ -3410,7 +3401,7 @@ class AllPlatformTests(BasePlatformTests):
 
         def hg_init(project_dir):
             subprocess.check_call(['hg', 'init'], cwd=project_dir)
-            with open(os.path.join(project_dir, '.hg', 'hgrc'), 'w') as f:
+            with open(os.path.join(project_dir, '.hg', 'hgrc'), 'w', encoding='utf-8') as f:
                 print('[ui]', file=f)
                 print('username=Author Person <teh_coderz@example.com>', file=f)
             subprocess.check_call(['hg', 'add', 'meson.build', 'distexe.c'], cwd=project_dir)
@@ -3451,7 +3442,7 @@ class AllPlatformTests(BasePlatformTests):
     def create_dummy_subproject(self, project_dir, name):
         path = os.path.join(project_dir, 'subprojects', name)
         os.makedirs(path)
-        with open(os.path.join(path, 'meson.build'), 'w') as ofile:
+        with open(os.path.join(path, 'meson.build'), 'w', encoding='utf-8') as ofile:
             ofile.write(f"project('{name}', version: '1.0')")
         return path
 
@@ -3459,7 +3450,7 @@ class AllPlatformTests(BasePlatformTests):
         # Create this on the fly because having rogue .git directories inside
         # the source tree leads to all kinds of trouble.
         with tempfile.TemporaryDirectory() as project_dir:
-            with open(os.path.join(project_dir, 'meson.build'), 'w') as ofile:
+            with open(os.path.join(project_dir, 'meson.build'), 'w', encoding='utf-8') as ofile:
                 ofile.write(textwrap.dedent('''\
                     project('disttest', 'c', version : '1.4.3')
                     e = executable('distexe', 'distexe.c')
@@ -3468,7 +3459,7 @@ class AllPlatformTests(BasePlatformTests):
                     subproject('tarballsub', required : false)
                     subproject('samerepo', required : false)
                     '''))
-            with open(os.path.join(project_dir, 'distexe.c'), 'w') as ofile:
+            with open(os.path.join(project_dir, 'distexe.c'), 'w', encoding='utf-8') as ofile:
                 ofile.write(textwrap.dedent('''\
                     #include<stdio.h>
 
@@ -3558,7 +3549,7 @@ class AllPlatformTests(BasePlatformTests):
                 xz_checksumfile = xz_distfile + '.sha256sum'
                 self.assertPathExists(xz_distfile)
                 self.assertPathExists(xz_checksumfile)
-                tar = tarfile.open(xz_distfile, "r:xz")
+                tar = tarfile.open(xz_distfile, "r:xz")  # [ignore encoding]
                 self.assertEqual(sorted(['samerepo-1.0',
                                          'samerepo-1.0/meson.build']),
                                  sorted([i.name for i in tar]))
@@ -4092,12 +4083,12 @@ class AllPlatformTests(BasePlatformTests):
             # test directory with existing code file
             if lang in {'c', 'cpp', 'd'}:
                 with tempfile.TemporaryDirectory() as tmpdir:
-                    with open(os.path.join(tmpdir, 'foo.' + lang), 'w') as f:
+                    with open(os.path.join(tmpdir, 'foo.' + lang), 'w', encoding='utf-8') as f:
                         f.write('int main(void) {}')
                     self._run(self.meson_command + ['init', '-b'], workdir=tmpdir)
             elif lang in {'java'}:
                 with tempfile.TemporaryDirectory() as tmpdir:
-                    with open(os.path.join(tmpdir, 'Foo.' + lang), 'w') as f:
+                    with open(os.path.join(tmpdir, 'Foo.' + lang), 'w', encoding='utf-8') as f:
                         f.write('public class Foo { public static void main() {} }')
                     self._run(self.meson_command + ['init', '-b'], workdir=tmpdir)
 
@@ -4489,7 +4480,7 @@ class AllPlatformTests(BasePlatformTests):
         with tempfile.TemporaryDirectory() as containing:
             with tempfile.TemporaryDirectory(dir=containing) as srcdir:
                 mfile = os.path.join(srcdir, 'meson.build')
-                of = open(mfile, 'w')
+                of = open(mfile, 'w', encoding='utf-8')
                 of.write("project('foobar', 'c')\n")
                 of.close()
                 pc = subprocess.run(self.setup_command,
@@ -4614,7 +4605,7 @@ class AllPlatformTests(BasePlatformTests):
 
         # Create a file in builddir and verify wipe command removes it
         filename = os.path.join(self.builddir, 'something')
-        open(filename, 'w').close()
+        open(filename, 'w', encoding='utf-8').close()
         self.assertTrue(os.path.exists(filename))
         out = self.init(testdir, extra_args=['--wipe', '-Dopt4=val4'])
         self.assertFalse(os.path.exists(filename))
@@ -4771,13 +4762,13 @@ class AllPlatformTests(BasePlatformTests):
             shutil.copyfile(badfile, testfile)
             shutil.copyfile(badheader, testheader)
             self.init(testdir)
-            self.assertNotEqual(Path(testfile).read_text(),
-                                Path(goodfile).read_text())
-            self.assertNotEqual(Path(testheader).read_text(),
-                                Path(goodheader).read_text())
+            self.assertNotEqual(Path(testfile).read_text(encoding='utf-8'),
+                                Path(goodfile).read_text(encoding='utf-8'))
+            self.assertNotEqual(Path(testheader).read_text(encoding='utf-8'),
+                                Path(goodheader).read_text(encoding='utf-8'))
             self.run_target('clang-format')
-            self.assertEqual(Path(testheader).read_text(),
-                             Path(goodheader).read_text())
+            self.assertEqual(Path(testheader).read_text(encoding='utf-8'),
+                             Path(goodheader).read_text(encoding='utf-8'))
         finally:
             if os.path.exists(testfile):
                 os.unlink(testfile)
@@ -4837,7 +4828,7 @@ class AllPlatformTests(BasePlatformTests):
         infodir = os.path.join(self.builddir, 'meson-info')
         self.assertPathExists(infodir)
 
-        with open(os.path.join(infodir, 'intro-targets.json')) as fp:
+        with open(os.path.join(infodir, 'intro-targets.json'), encoding='utf-8') as fp:
             targets = json.load(fp)
 
         for i in targets:
@@ -4946,7 +4937,7 @@ class AllPlatformTests(BasePlatformTests):
         for i in root_keylist:
             curr = os.path.join(infodir, 'intro-{}.json'.format(i[0]))
             self.assertPathExists(curr)
-            with open(curr) as fp:
+            with open(curr, encoding='utf-8') as fp:
                 res[i[0]] = json.load(fp)
 
         assertKeyTypes(root_keylist, res)
@@ -5068,7 +5059,7 @@ class AllPlatformTests(BasePlatformTests):
         for i in root_keylist:
             curr = os.path.join(infodir, f'intro-{i}.json')
             self.assertPathExists(curr)
-            with open(curr) as fp:
+            with open(curr, encoding='utf-8') as fp:
                 res_file[i] = json.load(fp)
 
         self.assertEqual(res_all, res_file)
@@ -5078,7 +5069,7 @@ class AllPlatformTests(BasePlatformTests):
         introfile = os.path.join(self.builddir, 'meson-info', 'meson-info.json')
         self.init(testdir)
         self.assertPathExists(introfile)
-        with open(introfile) as fp:
+        with open(introfile, encoding='utf-8') as fp:
             res1 = json.load(fp)
 
         for i in ['meson_version', 'directories', 'introspection', 'build_files_updated', 'error']:
@@ -5092,7 +5083,7 @@ class AllPlatformTests(BasePlatformTests):
         introfile = os.path.join(self.builddir, 'meson-info', 'intro-buildoptions.json')
         self.init(testdir)
         self.assertPathExists(introfile)
-        with open(introfile) as fp:
+        with open(introfile, encoding='utf-8') as fp:
             res1 = json.load(fp)
 
         for i in res1:
@@ -5110,7 +5101,7 @@ class AllPlatformTests(BasePlatformTests):
         self.setconf('-Dcpp_std=c++14')
         self.setconf('-Dbuildtype=release')
 
-        with open(introfile) as fp:
+        with open(introfile, encoding='utf-8') as fp:
             res2 = json.load(fp)
 
         self.assertListEqual(res1, res2)
@@ -5121,7 +5112,7 @@ class AllPlatformTests(BasePlatformTests):
         introfile = os.path.join(self.builddir, 'meson-info', 'intro-targets.json')
         self.init(testdir)
         self.assertPathExists(introfile)
-        with open(introfile) as fp:
+        with open(introfile, encoding='utf-8') as fp:
             res_wb = json.load(fp)
 
         res_nb = self.introspect_directory(testfile, ['--targets'] + self.meson_args)
@@ -5663,13 +5654,13 @@ class AllPlatformTests(BasePlatformTests):
 
     def test_cross_file_constants(self):
         with temp_filename() as crossfile1, temp_filename() as crossfile2:
-            with open(crossfile1, 'w') as f:
+            with open(crossfile1, 'w', encoding='utf-8') as f:
                 f.write(textwrap.dedent(
                     '''
                     [constants]
                     compiler = 'gcc'
                     '''))
-            with open(crossfile2, 'w') as f:
+            with open(crossfile2, 'w', encoding='utf-8') as f:
                 f.write(textwrap.dedent(
                     '''
                     [constants]
@@ -5699,7 +5690,7 @@ class AllPlatformTests(BasePlatformTests):
             upstream = os.path.join(srcdir, 'subprojects', 'wrap_git_upstream')
             upstream_uri = Path(upstream).as_uri()
             _git_init(upstream)
-            with open(os.path.join(srcdir, 'subprojects', 'wrap_git.wrap'), 'w') as f:
+            with open(os.path.join(srcdir, 'subprojects', 'wrap_git.wrap'), 'w', encoding='utf-8') as f:
                 f.write(textwrap.dedent('''
                   [wrap-git]
                   url = {}
@@ -5723,7 +5714,7 @@ class AllPlatformTests(BasePlatformTests):
     def test_nostdlib(self):
         testdir = os.path.join(self.unit_test_dir, '78 nostdlib')
         machinefile = os.path.join(self.builddir, 'machine.txt')
-        with open(machinefile, 'w') as f:
+        with open(machinefile, 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent('''
                 [properties]
                 c_stdlib = 'mylibc'
@@ -5752,7 +5743,7 @@ class AllPlatformTests(BasePlatformTests):
         os.makedirs(os.path.dirname(real_wrap))
 
         # Invalid redirect, filename must have .wrap extension
-        with open(redirect_wrap, 'w') as f:
+        with open(redirect_wrap, 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent('''
                 [wrap-redirect]
                 filename = foo/subprojects/real.wrapper
@@ -5761,7 +5752,7 @@ class AllPlatformTests(BasePlatformTests):
             PackageDefinition(redirect_wrap)
 
         # Invalid redirect, filename cannot be in parent directory
-        with open(redirect_wrap, 'w') as f:
+        with open(redirect_wrap, 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent('''
                 [wrap-redirect]
                 filename = ../real.wrap
@@ -5770,7 +5761,7 @@ class AllPlatformTests(BasePlatformTests):
             PackageDefinition(redirect_wrap)
 
         # Invalid redirect, filename must be in foo/subprojects/real.wrap
-        with open(redirect_wrap, 'w') as f:
+        with open(redirect_wrap, 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent('''
                 [wrap-redirect]
                 filename = foo/real.wrap
@@ -5779,12 +5770,12 @@ class AllPlatformTests(BasePlatformTests):
             wrap = PackageDefinition(redirect_wrap)
 
         # Correct redirect
-        with open(redirect_wrap, 'w') as f:
+        with open(redirect_wrap, 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent('''
                 [wrap-redirect]
                 filename = foo/subprojects/real.wrap
                 '''))
-        with open(real_wrap, 'w') as f:
+        with open(real_wrap, 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent('''
                 [wrap-git]
                 url = http://invalid
@@ -5801,7 +5792,7 @@ class AllPlatformTests(BasePlatformTests):
         cmakefile = Path(testdir) / 'subprojects' / 'sub2' / 'CMakeLists.txt'
         self.init(testdir)
         self.build()
-        with cmakefile.open('a') as f:
+        with cmakefile.open('a', encoding='utf-8') as f:
             os.utime(str(cmakefile))
         self.assertReconfiguredBuildIsNoop()
 
@@ -5991,7 +5982,7 @@ class FailureTests(BasePlatformTests):
         '''
         if langs is None:
             langs = []
-        with open(self.mbuild, 'w') as f:
+        with open(self.mbuild, 'w', encoding='utf-8') as f:
             f.write("project('failure test', 'c', 'cpp'")
             if meson_version:
                 f.write(f", meson_version: '{meson_version}'")
@@ -6000,7 +5991,7 @@ class FailureTests(BasePlatformTests):
                 f.write(f"add_languages('{lang}', required : false)\n")
             f.write(contents)
         if options is not None:
-            with open(self.moptions, 'w') as f:
+            with open(self.moptions, 'w', encoding='utf-8') as f:
                 f.write(options)
         o = {'MESON_FORCE_BACKTRACE': '1'}
         if override_envvars is None:
@@ -6017,7 +6008,7 @@ class FailureTests(BasePlatformTests):
     def obtainMesonOutput(self, contents, match, extra_args, langs, meson_version=None):
         if langs is None:
             langs = []
-        with open(self.mbuild, 'w') as f:
+        with open(self.mbuild, 'w', encoding='utf-8') as f:
             f.write("project('output test', 'c', 'cpp'")
             if meson_version:
                 f.write(f", meson_version: '{meson_version}'")
@@ -6838,7 +6829,7 @@ class LinuxlikeTests(BasePlatformTests):
         }
         if is_osx() or is_haiku():
             expected['Cflags'] = expected['Cflags'].replace('-pthread ', '')
-        with open(os.path.join(privatedir2, 'dependency-test.pc')) as f:
+        with open(os.path.join(privatedir2, 'dependency-test.pc'), encoding='utf-8') as f:
             matched_lines = 0
             for line in f:
                 parts = line.split(':', 1)
@@ -6869,16 +6860,16 @@ class LinuxlikeTests(BasePlatformTests):
         self.assertEqual(out, ['-llibmain2', '-llibinternal'])
 
         # See common/44 pkgconfig-gen/meson.build for description of the case this test
-        with open(os.path.join(privatedir1, 'simple2.pc')) as f:
+        with open(os.path.join(privatedir1, 'simple2.pc'), encoding='utf-8') as f:
             content = f.read()
             self.assertIn('Libs: -L${libdir} -lsimple2 -lsimple1', content)
             self.assertIn('Libs.private: -lz', content)
 
-        with open(os.path.join(privatedir1, 'simple3.pc')) as f:
+        with open(os.path.join(privatedir1, 'simple3.pc'), encoding='utf-8') as f:
             content = f.read()
             self.assertEqual(1, content.count('-lsimple3'))
 
-        with open(os.path.join(privatedir1, 'simple5.pc')) as f:
+        with open(os.path.join(privatedir1, 'simple5.pc'), encoding='utf-8') as f:
             content = f.read()
             self.assertNotIn('-lstat2', content)
 
@@ -6901,7 +6892,7 @@ class LinuxlikeTests(BasePlatformTests):
     def test_pkg_unfound(self):
         testdir = os.path.join(self.unit_test_dir, '23 unfound pkgconfig')
         self.init(testdir)
-        with open(os.path.join(self.privatedir, 'somename.pc')) as f:
+        with open(os.path.join(self.privatedir, 'somename.pc'), encoding='utf-8') as f:
             pcfile = f.read()
         self.assertFalse('blub_blob_blib' in pcfile)
 
@@ -7421,7 +7412,7 @@ class LinuxlikeTests(BasePlatformTests):
                           ('-L/me/fourth', '-lfoo4'),
                           ('-lfoo3', '-lfoo4'),
                           ]
-        with open(os.path.join(self.builddir, 'build.ninja')) as ifile:
+        with open(os.path.join(self.builddir, 'build.ninja'), encoding='utf-8') as ifile:
             for line in ifile:
                 if expected_order[0][0] in line:
                     for first, second in expected_order:
@@ -7833,7 +7824,7 @@ class LinuxlikeTests(BasePlatformTests):
         '''
         testdir = os.path.join(self.unit_test_dir, '43 dep order')
         self.init(testdir)
-        with open(os.path.join(self.builddir, 'build.ninja')) as bfile:
+        with open(os.path.join(self.builddir, 'build.ninja'), encoding='utf-8') as bfile:
             for line in bfile:
                 if 'build myexe:' in line or 'build myexe.exe:' in line:
                     self.assertIn('liblib1.a liblib2.a', line)
@@ -7852,7 +7843,7 @@ class LinuxlikeTests(BasePlatformTests):
             rpathre = re.compile(r'-rpath,.*/subprojects/sub1.*-rpath,.*/subprojects/sub2')
         else:
             rpathre = re.compile(r'-rpath,\$\$ORIGIN/subprojects/sub1:\$\$ORIGIN/subprojects/sub2')
-        with open(os.path.join(self.builddir, 'build.ninja')) as bfile:
+        with open(os.path.join(self.builddir, 'build.ninja'), encoding='utf-8') as bfile:
             for line in bfile:
                 if '-rpath' in line:
                     self.assertRegex(line, rpathre)
@@ -7865,7 +7856,7 @@ class LinuxlikeTests(BasePlatformTests):
         '''
         testdir = os.path.join(self.src_root, 'test cases', 'native', '9 override with exe')
         self.init(testdir)
-        with open(os.path.join(self.builddir, 'build.ninja')) as bfile:
+        with open(os.path.join(self.builddir, 'build.ninja'), encoding='utf-8') as bfile:
             for line in bfile:
                 if 'main1.c:' in line or 'main2.c:' in line:
                     self.assertIn('| subprojects/sub/foobar', line)
@@ -8206,7 +8197,7 @@ class LinuxlikeTests(BasePlatformTests):
             patch_filename = foo-patch.tar.xz
             patch_hash = {}
             """.format(source_filename, source_hash, patch_filename, patch_hash))
-        with open(wrap_filename, 'w') as f:
+        with open(wrap_filename, 'w', encoding='utf-8') as f:
             f.write(wrap)
         self.init(testdir)
         self.build()
@@ -8234,7 +8225,7 @@ class LinuxlikeTests(BasePlatformTests):
         # the 2nd dependency() to lookup on system.
         self.new_builddir()
         with tempfile.TemporaryDirectory() as d:
-            with open(os.path.join(d, 'meson.build'), 'w') as f:
+            with open(os.path.join(d, 'meson.build'), 'w', encoding='utf-8') as f:
                 f.write(textwrap.dedent('''\
                     project('test')
                     dependency('notfound', fallback: 'broken', required: false)
@@ -8245,10 +8236,10 @@ class LinuxlikeTests(BasePlatformTests):
     def test_as_link_whole(self):
         testdir = os.path.join(self.unit_test_dir, '77 as link whole')
         self.init(testdir)
-        with open(os.path.join(self.privatedir, 'bar1.pc')) as f:
+        with open(os.path.join(self.privatedir, 'bar1.pc'), encoding='utf-8') as f:
             content = f.read()
             self.assertIn('-lfoo', content)
-        with open(os.path.join(self.privatedir, 'bar2.pc')) as f:
+        with open(os.path.join(self.privatedir, 'bar2.pc'), encoding='utf-8') as f:
             content = f.read()
             self.assertNotIn('-lfoo', content)
 
@@ -8848,7 +8839,7 @@ class NativeFileTests(BasePlatformTests):
         """
         filename = os.path.join(self.builddir, f'generated{self.current_config}.config')
         self.current_config += 1
-        with open(filename, 'wt') as f:
+        with open(filename, 'wt', encoding='utf-8') as f:
             for section, entries in values.items():
                 f.write(f'[{section}]\n')
                 for k, v in entries.items():
@@ -8870,7 +8861,7 @@ class NativeFileTests(BasePlatformTests):
         else:
             chbang = '#!/usr/bin/env python3'
 
-        with open(filename, 'wt') as f:
+        with open(filename, 'wt', encoding='utf-8') as f:
             f.write(textwrap.dedent('''\
                 {}
                 import argparse
@@ -8908,7 +8899,7 @@ class NativeFileTests(BasePlatformTests):
         # invoke python files itself, so instead we generate a .bat file, which
         # invokes our python wrapper
         batfile = os.path.join(self.builddir, f'binary_wrapper{self.current_wrapper}.bat')
-        with open(batfile, 'wt') as f:
+        with open(batfile, 'wt', encoding='utf-8') as f:
             f.write(fr'@{sys.executable} {filename} %*')
         return batfile
 
@@ -8942,7 +8933,7 @@ class NativeFileTests(BasePlatformTests):
             wrapper = self.helper_create_binary_wrapper('bash', d, version='12345')
 
             def filler():
-                with open(fifo, 'w') as f:
+                with open(fifo, 'w', encoding='utf-8') as f:
                     f.write('[binaries]\n')
                     f.write(f"bash = '{wrapper}'\n")
 
@@ -9427,7 +9418,7 @@ class CrossFileTests(BasePlatformTests):
         testdir = os.path.join(self.unit_test_dir, '71 cross test passed')
         with tempfile.TemporaryDirectory() as d:
             p = Path(d) / 'crossfile'
-            with p.open('wt') as f:
+            with p.open('wt', encoding='utf-8') as f:
                 f.write(self._cross_file_generator(needs_exe_wrapper=True))
             self.init(testdir, extra_args=['--cross-file=' + str(p)])
             out = self.run_target('test')
@@ -9437,7 +9428,7 @@ class CrossFileTests(BasePlatformTests):
         testdir = os.path.join(self.unit_test_dir, '71 cross test passed')
         with tempfile.TemporaryDirectory() as d:
             p = Path(d) / 'crossfile'
-            with p.open('wt') as f:
+            with p.open('wt', encoding='utf-8') as f:
                 f.write(self._cross_file_generator(needs_exe_wrapper=False))
             self.init(testdir, extra_args=['--cross-file=' + str(p)])
             out = self.run_target('test')
@@ -9447,11 +9438,11 @@ class CrossFileTests(BasePlatformTests):
         testdir = os.path.join(self.unit_test_dir, '71 cross test passed')
         with tempfile.TemporaryDirectory() as d:
             s = Path(d) / 'wrapper.py'
-            with s.open('wt') as f:
+            with s.open('wt', encoding='utf-8') as f:
                 f.write(self._stub_exe_wrapper())
             s.chmod(0o774)
             p = Path(d) / 'crossfile'
-            with p.open('wt') as f:
+            with p.open('wt', encoding='utf-8') as f:
                 f.write(self._cross_file_generator(
                     needs_exe_wrapper=True,
                     exe_wrapper=[str(s)]))
@@ -9464,7 +9455,7 @@ class CrossFileTests(BasePlatformTests):
         testdir = os.path.join(self.unit_test_dir, '71 cross test passed')
         with tempfile.TemporaryDirectory() as d:
             p = Path(d) / 'crossfile'
-            with p.open('wt') as f:
+            with p.open('wt', encoding='utf-8') as f:
                 f.write(self._cross_file_generator(needs_exe_wrapper=True))
 
             self.init(testdir, extra_args=['--cross-file=' + str(p)])
@@ -9522,7 +9513,7 @@ class CrossFileTests(BasePlatformTests):
         """
         filename = os.path.join(self.builddir, f'generated{self.current_config}.config')
         self.current_config += 1
-        with open(filename, 'wt') as f:
+        with open(filename, 'wt', encoding='utf-8') as f:
             for section, entries in values.items():
                 f.write(f'[{section}]\n')
                 for k, v in entries.items():
@@ -9996,7 +9987,7 @@ class SubprojectsCommandTests(BasePlatformTests):
 
     def _create_project(self, path, project_name='dummy'):
         os.makedirs(str(path), exist_ok=True)
-        with open(str(path / 'meson.build'), 'w') as f:
+        with open(str(path / 'meson.build'), 'w', encoding='utf-8') as f:
             f.write(f"project('{project_name}')")
 
     def _git(self, cmd, workdir):
@@ -10058,7 +10049,7 @@ class SubprojectsCommandTests(BasePlatformTests):
 
     def _wrap_create_git(self, name, revision='master'):
         path = self.root_dir / name
-        with open(str((self.subprojects_dir / name).with_suffix('.wrap')), 'w') as f:
+        with open(str((self.subprojects_dir / name).with_suffix('.wrap')), 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent(
                 '''
                 [wrap-git]
@@ -10068,7 +10059,7 @@ class SubprojectsCommandTests(BasePlatformTests):
 
     def _wrap_create_file(self, name, tarball='dummy.tar.gz'):
         path = self.root_dir / tarball
-        with open(str((self.subprojects_dir / name).with_suffix('.wrap')), 'w') as f:
+        with open(str((self.subprojects_dir / name).with_suffix('.wrap')), 'w', encoding='utf-8') as f:
             f.write(textwrap.dedent(
                 f'''
                 [wrap-file]
diff --git a/tools/ac_converter.py b/tools/ac_converter.py
index 6c72f8d..c3b954c 100755
--- a/tools/ac_converter.py
+++ b/tools/ac_converter.py
@@ -371,7 +371,7 @@ if len(sys.argv) != 2:
     print(help_message.format(sys.argv[0]))
     sys.exit(0)
 
-with open(sys.argv[1]) as f:
+with open(sys.argv[1], encoding='utf-8') as f:
     for line in f:
         line = line.strip()
         arr = line.split()
diff --git a/tools/boost_names.py b/tools/boost_names.py
index 89926ec..b716ccb 100755
--- a/tools/boost_names.py
+++ b/tools/boost_names.py
@@ -78,7 +78,7 @@ class BoostModule():
 
 
 def get_boost_version() -> T.Optional[str]:
-    raw = jamroot.read_text()
+    raw = jamroot.read_text(encoding='utf-8')
     m = re.search(r'BOOST_VERSION\s*:\s*([0-9\.]+)\s*;', raw)
     if m:
         return m.group(1)
@@ -91,7 +91,7 @@ def get_libraries(jamfile: Path) -> T.List[BoostLibrary]:
     #  - compiler flags
 
     libs: T.List[BoostLibrary] = []
-    raw = jamfile.read_text()
+    raw = jamfile.read_text(encoding='utf-8')
     raw = re.sub(r'#.*\n', '\n', raw)  # Remove comments
     raw = re.sub(r'\s+', ' ', raw)     # Force single space
     raw = re.sub(r'}', ';', raw)       # Cheat code blocks by converting } to ;
@@ -185,7 +185,7 @@ def process_lib_dir(ldir: Path) -> T.List[BoostModule]:
         libs = get_libraries(bjam_file)
 
     # Extract metadata
-    data = json.loads(meta_file.read_text())
+    data = json.loads(meta_file.read_text(encoding='utf-8'))
     if not isinstance(data, list):
         data = [data]
 
diff --git a/tools/cmake2meson.py b/tools/cmake2meson.py
index 4185b5a..a12d9cf 100755
--- a/tools/cmake2meson.py
+++ b/tools/cmake2meson.py
@@ -280,13 +280,13 @@ class Converter:
             subdir = self.cmake_root
         cfile = Path(subdir).expanduser() / 'CMakeLists.txt'
         try:
-            with cfile.open() as f:
+            with cfile.open(encoding='utf-8') as f:
                 cmakecode = f.read()
         except FileNotFoundError:
             print('\nWarning: No CMakeLists.txt in', subdir, '\n', file=sys.stderr)
             return
         p = Parser(cmakecode)
-        with (subdir / 'meson.build').open('w') as outfile:
+        with (subdir / 'meson.build').open('w', encoding='utf-8') as outfile:
             for t in p.parse():
                 if t.name == 'add_subdirectory':
                     # print('\nRecursing to subdir',
@@ -300,7 +300,7 @@ class Converter:
 
     def write_options(self) -> None:
         filename = self.cmake_root / 'meson_options.txt'
-        with filename.open('w') as optfile:
+        with filename.open('w', encoding='utf-8') as optfile:
             for o in self.options:
                 (optname, description, default) = o
                 if default is None:
diff --git a/tools/dircondenser.py b/tools/dircondenser.py
index 9d642d2..2a726df 100755
--- a/tools/dircondenser.py
+++ b/tools/dircondenser.py
@@ -54,11 +54,11 @@ def get_entries() -> T.List[T.Tuple[int, str]]:
     return entries
 
 def replace_source(sourcefile: str, replacements: T.List[T.Tuple[str, str]]) -> None:
-    with open(sourcefile) as f:
+    with open(sourcefile, encoding='utf-8') as f:
         contents = f.read()
     for old_name, new_name in replacements:
         contents = contents.replace(old_name, new_name)
-    with open(sourcefile, 'w') as f:
+    with open(sourcefile, 'w', encoding='utf-8') as f:
         f.write(contents)
 
 def condense(dirname: str) -> None:
diff --git a/tools/gen_data.py b/tools/gen_data.py
index 9affc66..b1c62e0 100755
--- a/tools/gen_data.py
+++ b/tools/gen_data.py
@@ -107,7 +107,7 @@ def main() -> int:
 
             def write_once(self, path: Path) -> None:
                 if not path.exists():
-                    path.write_text(self.data)
+                    path.write_text(self.data, encoding='utf-8')
 
             def write_to_private(self, env: 'Environment') -> Path:
                 out_file = Path(env.scratch_dir) / 'data' / self.path.name
@@ -133,7 +133,7 @@ def main() -> int:
     ''')
 
     print(f'Updating {out_file}')
-    out_file.write_text(data)
+    out_file.write_text(data, encoding='utf-8')
     return 0
 
 if __name__ == '__main__':
diff --git a/tools/regenerate_docs.py b/tools/regenerate_docs.py
index f5ce77b..2029314 100755
--- a/tools/regenerate_docs.py
+++ b/tools/regenerate_docs.py
@@ -114,13 +114,13 @@ def generate_hotdoc_includes(root_dir: Path, output_dir: Path) -> None:
 
     for cmd, parsed in cmd_data.items():
         for typ in parsed.keys():
-            with open(output_dir / (cmd+'_'+typ+'.inc'), 'w') as f:
+            with open(output_dir / (cmd+'_'+typ+'.inc'), 'w', encoding='utf-8') as f:
                 f.write(parsed[typ])
 
 def generate_wrapdb_table(output_dir: Path) -> None:
     url = urlopen('https://wrapdb.mesonbuild.com/v2/releases.json')
     releases = json.loads(url.read().decode())
-    with open(output_dir / 'wrapdb-table.md', 'w') as f:
+    with open(output_dir / 'wrapdb-table.md', 'w', encoding='utf-8') as f:
         f.write('| Project | Versions | Provided dependencies | Provided programs |\n')
         f.write('| ------- | -------- | --------------------- | ----------------- |\n')
         for name, info in releases.items():
@@ -147,7 +147,7 @@ def regenerate_docs(output_dir: PathLike,
     generate_wrapdb_table(output_dir)
 
     if dummy_output_file:
-        with open(output_dir/dummy_output_file, 'w') as f:
+        with open(output_dir/dummy_output_file, 'w', encoding='utf-8') as f:
             f.write('dummy file for custom_target output')
 
 if __name__ == '__main__':
diff --git a/tools/run_with_cov.py b/tools/run_with_cov.py
index 17fb300..3f78efc 100755
--- a/tools/run_with_cov.py
+++ b/tools/run_with_cov.py
@@ -28,9 +28,9 @@ from mesonbuild import mesonlib
 def generate_coveragerc() -> Path:
     i_file = (root_path / 'data' / '.coveragerc.in')
     o_file = (root_path / '.coveragerc')
-    raw = i_file.read_text()
+    raw = i_file.read_text(encoding='utf-8')
     raw = raw.replace('@ROOT@', root_path.as_posix())
-    o_file.write_text(raw)
+    o_file.write_text(raw, encoding='utf-8')
     return o_file
 
 def main() -> int: