Merge pull request #4035 from jon-turney/factor-out-version-check

 Apply dependency(version:) check for all dependency types

24 files changed, 145 insertions, 67 deletions

diff --git a/docs/markdown/Reference-manual.md b/docs/markdown/Reference-manual.md
index 6cf7552..6d2b2da 100644
--- a/docs/markdown/Reference-manual.md
+++ b/docs/markdown/Reference-manual.md
@@ -380,11 +380,12 @@ otherwise. This function supports the following keyword arguments:
 - `static` tells the dependency provider to try to get static
   libraries instead of dynamic ones (note that this is not supported
   by all dependency backends)
-- `version`, specifies the required version, a string containing a
+- `version` specifies the required version, a string containing a
   comparison operator followed by the version string, examples include
   `>1.0.0`, `<=2.3.5` or `3.1.4` for exact matching. (*Added 0.37.0*)
   You can also specify multiple restrictions by passing a list to this
   keyword argument, such as: `['>=3.14.0', '<=4.1.0']`.
+  These requirements are never met if the version is unknown.
 - other
 [library-specific](Dependencies.md#dependencies-with-custom-lookup-functionality)
 keywords may also be accepted (e.g. `modules` specifies submodules to use for
@@ -1986,7 +1987,9 @@ an external dependency with the following methods:
    with `declare_dependency()` and `pkgconfig` for system dependencies
    obtained with Pkg-config.
 
- - `version()` is the version number as a string, for example `1.2.8`
+ - `version()` is the version number as a string, for example `1.2.8`.
+   `unknown` if the dependency provider doesn't support determining the
+   version.
 
  - `partial_dependency(compile_args : false, link_args : false, links
    : false, includes : false, source : false)` (*added 0.46.0*) returns
diff --git a/docs/markdown/snippets/dependency_version.md b/docs/markdown/snippets/dependency_version.md
new file mode 100644
index 0000000..4bbf346
--- /dev/null
+++ b/docs/markdown/snippets/dependency_version.md
@@ -0,0 +1,14 @@
+## `dependency(version:)` now applies to all dependency types
+
+Previously, version constraints were only enforced for dependencies found using
+the pkg-config dependency provider.  These constraints now apply to dependencies
+found using any dependency provider.
+
+Some combinations of dependency, host and method do not currently support
+discovery of the version.  In these cases, the dependency will not be found if a
+version constraint is applied, otherwise the `version()` method for the
+dependency object will return `'unknown'`.
+
+(If discovering the version in one of these combinations is important to you,
+and a method exists to determine the version in that case, please file an issue
+with as much information as possible.)
diff --git a/mesonbuild/dependencies/base.py b/mesonbuild/dependencies/base.py
index 94ae217..04c4701 100644
--- a/mesonbuild/dependencies/base.py
+++ b/mesonbuild/dependencies/base.py
@@ -98,7 +98,7 @@ class Dependency:
 
     def __init__(self, type_name, kwargs):
         self.name = "null"
-        self.version = 'none'
+        self.version = None
         self.language = None # None means C-like
         self.is_found = False
         self.type_name = type_name
@@ -138,7 +138,10 @@ class Dependency:
         return self.name
 
     def get_version(self):
-        return self.version
+        if self.version:
+            return self.version
+        else:
+            return 'unknown'
 
     def get_exe_args(self, compiler):
         return []
@@ -218,6 +221,8 @@ class ExternalDependency(Dependency):
         self.is_found = False
         self.language = language
         self.version_reqs = kwargs.get('version', None)
+        if isinstance(self.version_reqs, str):
+            self.version_reqs = [self.version_reqs]
         self.required = kwargs.get('required', True)
         self.silent = kwargs.get('silent', False)
         self.static = kwargs.get('static', False)
@@ -275,6 +280,41 @@ class ExternalDependency(Dependency):
     def log_tried(self):
         return ''
 
+    # Check if dependency version meets the requirements
+    def _check_version(self):
+        if not self.is_found:
+            return
+
+        if self.version_reqs:
+            # an unknown version can never satisfy any requirement
+            if not self.version:
+                found_msg = ['Dependency', mlog.bold(self.name), 'found:']
+                found_msg += [mlog.red('NO'), 'unknown version, but need:',
+                              self.version_reqs]
+                mlog.log(*found_msg)
+
+                if self.required:
+                    m = 'Unknown version of dependency {!r}, but need {!r}.'
+                    raise DependencyException(m.format(self.name, self.version_reqs))
+
+            else:
+                (self.is_found, not_found, found) = \
+                    version_compare_many(self.version, self.version_reqs)
+                if not self.is_found:
+                    found_msg = ['Dependency', mlog.bold(self.name), 'found:']
+                    found_msg += [mlog.red('NO'),
+                                  'found {!r} but need:'.format(self.version),
+                                  ', '.join(["'{}'".format(e) for e in not_found])]
+                    if found:
+                        found_msg += ['; matched:',
+                                      ', '.join(["'{}'".format(e) for e in found])]
+                    mlog.log(*found_msg)
+
+                    if self.required:
+                        m = 'Invalid version of dependency, need {!r} {!r} found {!r}.'
+                        raise DependencyException(m.format(self.name, not_found, self.version))
+                    return
+
 
 class NotFoundDependency(Dependency):
     def __init__(self, environment):
@@ -375,7 +415,7 @@ class ConfigToolDependency(ExternalDependency):
             # don't fail with --version, in that case just assume that there is
             # only one version and return it.
             if not out:
-                return (tool, 'none')
+                return (tool, None)
             if versions:
                 is_found = version_compare_many(out, versions)[0]
                 # This allows returning a found version without a config tool,
@@ -480,20 +520,6 @@ class PkgConfigDependency(ExternalDependency):
         ret, self.version = self._call_pkgbin(['--modversion', name])
         if ret != 0:
             return
-        if self.version_reqs is None:
-            self.is_found = True
-        else:
-            if not isinstance(self.version_reqs, (str, list)):
-                raise DependencyException('Version argument must be string or list.')
-            if isinstance(self.version_reqs, str):
-                self.version_reqs = [self.version_reqs]
-            (self.is_found, not_found, found) = \
-                version_compare_many(self.version, self.version_reqs)
-            if not self.is_found:
-                if self.required:
-                    m = 'Invalid version of dependency, need {!r} {!r} found {!r}.'
-                    raise DependencyException(m.format(name, not_found, self.version))
-                return
 
         try:
             # Fetch cargs to be used while using this dependency
@@ -509,6 +535,8 @@ class PkgConfigDependency(ExternalDependency):
                 self.is_found = False
                 self.reason = e
 
+        self.is_found = True
+
     def __repr__(self):
         s = '<{0} {1}: {2} {3}>'
         return s.format(self.__class__.__name__, self.name, self.is_found,
@@ -862,22 +890,6 @@ class DubDependency(ExternalDependency):
                 self.pkg = package
                 break
 
-        # Check if package version meets the requirements
-        if self.version_reqs is None:
-            self.is_found = True
-        else:
-            if not isinstance(self.version_reqs, (str, list)):
-                raise DependencyException('Version argument must be string or list.')
-            if isinstance(self.version_reqs, str):
-                self.version_reqs = [self.version_reqs]
-            (self.is_found, not_found, found) = \
-                version_compare_many(self.version, self.version_reqs)
-            if not self.is_found:
-                if self.required:
-                    m = 'Invalid version of dependency, need {!r} {!r} found {!r}.'
-                    raise DependencyException(m.format(name, not_found, self.version))
-                return
-
         if self.pkg['targetFileName'].endswith('.a'):
             self.static = True
 
@@ -897,9 +909,7 @@ class DubDependency(ExternalDependency):
         for file in res:
             self.link_args.append(file)
 
-        if not found:
-            self.is_found = False
-            return
+        self.is_found = found
 
     def get_compiler(self):
         return self.compiler
@@ -1241,9 +1251,6 @@ class ExtraFrameworkDependency(ExternalDependency):
                 self.is_found = True
                 return
 
-    def get_version(self):
-        return 'unknown'
-
     def log_info(self):
         return os.path.join(self.path, self.name)
 
@@ -1291,6 +1298,8 @@ def find_external_dependency(name, env, kwargs):
     lname = name.lower()
     if lname not in _packages_accept_language and 'language' in kwargs:
         raise DependencyException('%s dependency does not accept "language" keyword argument' % (name, ))
+    if not isinstance(kwargs.get('version', ''), (str, list)):
+        raise DependencyException('Keyword "Version" must be string or list.')
 
     # display the dependency name with correct casing
     display_name = display_name_map.get(lname, lname)
@@ -1313,6 +1322,7 @@ def find_external_dependency(name, env, kwargs):
         # try this dependency method
         try:
             d = c()
+            d._check_version()
             pkgdep.append(d)
         except Exception as e:
             mlog.debug(str(e))
@@ -1333,7 +1343,7 @@ def find_external_dependency(name, env, kwargs):
                 if info:
                     info = ', ' + info
 
-                mlog.log(type_text, mlog.bold(display_name), details + 'found:', mlog.green('YES'), d.version + info)
+                mlog.log(type_text, mlog.bold(display_name), details + 'found:', mlog.green('YES'), (d.version if d.version else '') + info)
 
                 return d
 
diff --git a/mesonbuild/dependencies/dev.py b/mesonbuild/dependencies/dev.py
index 0cd3c2b..0876391 100644
--- a/mesonbuild/dependencies/dev.py
+++ b/mesonbuild/dependencies/dev.py
@@ -35,7 +35,6 @@ class GTestDependency(ExternalDependency):
         self.detect()
 
     def detect(self):
-        self.version = '1.something_maybe'
         gtest_detect = self.clib_compiler.find_library("gtest", self.env, [])
         gtest_main_detect = self.clib_compiler.find_library("gtest_main", self.env, [])
         if gtest_detect and (not self.main or gtest_main_detect):
@@ -85,7 +84,6 @@ class GTestDependency(ExternalDependency):
 class GMockDependency(ExternalDependency):
     def __init__(self, environment, kwargs):
         super().__init__('gmock', environment, 'cpp', kwargs)
-        self.version = '1.something_maybe'
         # GMock may be a library or just source.
         # Work with both.
         gmock_detect = self.clib_compiler.find_library("gmock", self.env, [])
diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index 78ce51b..014be84 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -180,7 +180,7 @@ class MPIDependency(ExternalDependency):
             if version:
                 version = version.group(0)
             else:
-                version = 'none'
+                version = None
 
             return version, cargs, libs
 
@@ -197,7 +197,7 @@ class MPIDependency(ExternalDependency):
                 return
             args = shlex.split(o)
 
-            version = 'none'
+            version = None
 
             return version, args, args
 
@@ -222,11 +222,11 @@ class MPIDependency(ExternalDependency):
         else:
             return
         if self.language == 'fortran':
-            return ('none',
+            return (None,
                     ['-I' + incdir, '-I' + os.path.join(incdir, post)],
                     [os.path.join(libdir, 'msmpi.lib'), os.path.join(libdir, 'msmpifec.lib')])
         else:
-            return ('none',
+            return (None,
                     ['-I' + incdir, '-I' + os.path.join(incdir, post)],
                     [os.path.join(libdir, 'msmpi.lib')])
 
@@ -267,17 +267,13 @@ class OpenMPDependency(ExternalDependency):
 
 class ThreadDependency(ExternalDependency):
     def __init__(self, environment, kwargs):
-        super().__init__('threads', environment, None, {})
+        super().__init__('threads', environment, None, kwargs)
         self.name = 'threads'
         self.is_found = True
-        mlog.log('Dependency', mlog.bold(self.name), 'found:', mlog.green('YES'))
 
     def need_threads(self):
         return True
 
-    def get_version(self):
-        return 'unknown'
-
 
 class Python3Dependency(ExternalDependency):
     def __init__(self, environment, kwargs):
@@ -447,8 +443,11 @@ class PcapDependency(ExternalDependency):
 
     @staticmethod
     def get_pcap_lib_version(ctdep):
-        return ctdep.clib_compiler.get_return_value('pcap_lib_version', 'string',
-                                                    '#include <pcap.h>', ctdep.env, [], [ctdep])
+        v = ctdep.clib_compiler.get_return_value('pcap_lib_version', 'string',
+                                                 '#include <pcap.h>', ctdep.env, [], [ctdep])
+        v = re.sub(r'libpcap version ', '', v)
+        v = re.sub(r' -- Apple version.*$', '', v)
+        return v
 
 
 class CupsDependency(ExternalDependency):
diff --git a/mesonbuild/dependencies/platform.py b/mesonbuild/dependencies/platform.py
index 5f89ccb..0c05156 100644
--- a/mesonbuild/dependencies/platform.py
+++ b/mesonbuild/dependencies/platform.py
@@ -33,8 +33,4 @@ class AppleFrameworks(ExternalDependency):
         for f in self.frameworks:
             self.link_args += ['-framework', f]
 
-    def found(self):
-        return mesonlib.is_osx()
-
-    def get_version(self):
-        return 'unknown'
+        self.is_found = mesonlib.is_osx()
diff --git a/mesonbuild/dependencies/ui.py b/mesonbuild/dependencies/ui.py
index c877f51..f19a76d 100644
--- a/mesonbuild/dependencies/ui.py
+++ b/mesonbuild/dependencies/ui.py
@@ -44,14 +44,12 @@ class GLDependency(ExternalDependency):
             # FIXME: Use AppleFrameworks dependency
             self.link_args = ['-framework', 'OpenGL']
             # FIXME: Detect version using self.clib_compiler
-            self.version = '1'
             return
         if mesonlib.is_windows():
             self.is_found = True
             # FIXME: Use self.clib_compiler.find_library()
             self.link_args = ['-lopengl32']
             # FIXME: Detect version using self.clib_compiler
-            self.version = '1'
             return
 
     @classmethod
@@ -63,7 +61,7 @@ class GLDependency(ExternalDependency):
             candidates.append(functools.partial(PkgConfigDependency, 'gl', environment, kwargs))
 
         if DependencyMethods.SYSTEM in methods:
-            candidates.append(functools.partial(GLDependency), environment, kwargs)
+            candidates.append(functools.partial(GLDependency, environment, kwargs))
 
         return candidates
 
@@ -224,7 +222,7 @@ class QtBaseDependency(ExternalDependency):
             self.compile_args = []
             self.link_args = []
             self.from_text = mlog.format_list(methods)
-            self.version = 'none'
+            self.version = None
 
     def compilers_detect(self):
         "Detect Qt (4 or 5) moc, uic, rcc in the specified bindir or in PATH"
@@ -557,7 +555,6 @@ class VulkanDependency(ExternalDependency):
 
             # TODO: find a way to retrieve the version from the sdk?
             # Usually it is a part of the path to it (but does not have to be)
-            self.version = '1'
             return
         else:
             # simply try to guess it, usually works on linux
@@ -565,7 +562,6 @@ class VulkanDependency(ExternalDependency):
             if libs is not None and self.clib_compiler.has_header('vulkan/vulkan.h', '', environment):
                 self.type_name = 'system'
                 self.is_found = True
-                self.version = 1 # TODO
                 for lib in libs:
                     self.link_args.append(lib)
                 return
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index 04e963a..4fbb837 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -2822,7 +2822,7 @@ external dependencies (including libraries) must go to "dependencies".''')
             return False
         found = dep.version_method([], {})
         # Don't do a version check if the dependency is not found and not required
-        if found == 'none' and not required:
+        if not dep.found_method([], {}) and not required:
             subproj_path = os.path.join(self.subproject_dir, dirname)
             mlog.log('Dependency', mlog.bold(name), 'from subproject',
                      mlog.bold(subproj_path), 'found:', mlog.red('NO'), '(cached)')
diff --git a/test cases/common/190 openmp/meson.build b/test cases/common/190 openmp/meson.build
index a05ca59..eb270ab 100644
--- a/test cases/common/190 openmp/meson.build
+++ b/test cases/common/190 openmp/meson.build
@@ -38,3 +38,6 @@ if add_languages('fortran', required : false)
 
   test('OpenMP Fortran', execpp, env : env)
 endif
+
+# Check we can apply a version constraint
+dependency('openmp', version: '>=@0@'.format(openmp.version()))
diff --git a/test cases/failing/81 framework dependency with version/meson.build b/test cases/failing/81 framework dependency with version/meson.build
new file mode 100644
index 0000000..714ad3b
--- /dev/null
+++ b/test cases/failing/81 framework dependency with version/meson.build
@@ -0,0 +1,4 @@
+project('framework dependency with version')
+# do individual frameworks have a meaningful version to test?  And multiple frameworks might be listed...
+# otherwise we're not on OSX and this will definitely fail
+dep = dependency('appleframeworks', modules: 'foundation', version: '>0')
diff --git a/test cases/failing/82 gl dependency with version/meson.build b/test cases/failing/82 gl dependency with version/meson.build
new file mode 100644
index 0000000..3014d43
--- /dev/null
+++ b/test cases/failing/82 gl dependency with version/meson.build
@@ -0,0 +1,9 @@
+project('gl dependency with version', 'c')
+
+host_system = host_machine.system()
+if host_system != 'windows' and host_system != 'darwin'
+  error('Test only fails on Windows and OSX')
+endif
+
+# gl dependency found via system method doesn't have a meaningful version to check
+dep = dependency('gl', method: 'system', version: '>0')
diff --git a/test cases/failing/83 threads dependency with version/meson.build b/test cases/failing/83 threads dependency with version/meson.build
new file mode 100644
index 0000000..6023fae
--- /dev/null
+++ b/test cases/failing/83 threads dependency with version/meson.build
@@ -0,0 +1,3 @@
+project('threads dependency with version', 'c')
+# threads dependency doesn't have a meaningful version to check
+dep = dependency('threads', version: '>0')
diff --git a/test cases/failing/84 gtest dependency with version/meson.build b/test cases/failing/84 gtest dependency with version/meson.build
new file mode 100644
index 0000000..5115f27
--- /dev/null
+++ b/test cases/failing/84 gtest dependency with version/meson.build
@@ -0,0 +1,3 @@
+project('gtest dependency with version', ['c', 'cpp'])
+# discovering gtest version is not yet implemented
+dep = dependency('gtest', version: '>0')
diff --git a/test cases/frameworks/1 boost/meson.build b/test cases/frameworks/1 boost/meson.build
index 9399598..d1e1da4 100644
--- a/test cases/frameworks/1 boost/meson.build
+++ b/test cases/frameworks/1 boost/meson.build
@@ -33,3 +33,6 @@ test('Boost nomod', nomodexe)
 test('Boost extralib test', extralibexe)
 
 subdir('partial_dep')
+
+# check we can apply a version constraint
+dependency('boost', version: '>=@0@'.format(dep.version()))
diff --git a/test cases/frameworks/15 llvm/meson.build b/test cases/frameworks/15 llvm/meson.build
index b5505eb..e05fddd 100644
--- a/test cases/frameworks/15 llvm/meson.build
+++ b/test cases/frameworks/15 llvm/meson.build
@@ -41,3 +41,6 @@ foreach static : [true, false]
     )
   endif
 endforeach
+
+# Check we can apply a version constraint
+dependency('llvm', version: '>=@0@'.format(d.version()))
diff --git a/test cases/frameworks/16 sdl2/meson.build b/test cases/frameworks/16 sdl2/meson.build
index 1bbf09f..fd90e36 100644
--- a/test cases/frameworks/16 sdl2/meson.build
+++ b/test cases/frameworks/16 sdl2/meson.build
@@ -15,3 +15,7 @@ configdep = dependency('sdl2', method : 'sdlconfig')
 
 # And the modern method name
 configdep = dependency('sdl2', method : 'config-tool')
+
+# Check we can apply a version constraint
+dependency('sdl2', version: '>=@0@'.format(sdl2_dep.version()), method: 'pkg-config')
+dependency('sdl2', version: '>=@0@'.format(sdl2_dep.version()), method: 'config-tool')
diff --git a/test cases/frameworks/17 mpi/meson.build b/test cases/frameworks/17 mpi/meson.build
index f3eacac..1085d40 100644
--- a/test cases/frameworks/17 mpi/meson.build
+++ b/test cases/frameworks/17 mpi/meson.build
@@ -42,3 +42,6 @@ if uburesult.returncode() != 0 and add_languages('fortran', required : false)
 
   test('MPI Fortran', exef)
 endif
+
+# Check we can apply a version constraint
+dependency('mpi', version: '>=@0@'.format(mpic.version()))
diff --git a/test cases/frameworks/18 vulkan/meson.build b/test cases/frameworks/18 vulkan/meson.build
index e98854e..5cfe89f 100644
--- a/test cases/frameworks/18 vulkan/meson.build
+++ b/test cases/frameworks/18 vulkan/meson.build
@@ -8,3 +8,6 @@ endif
 e = executable('vulkanprog', 'vulkanprog.c', dependencies : vulkan_dep)
 
 test('vulkantest', e)
+
+# Check we can apply a version constraint
+dependency('vulkan', version: '>=@0@'.format(vulkan_dep.version()))
diff --git a/test cases/frameworks/19 pcap/meson.build b/test cases/frameworks/19 pcap/meson.build
index eb6fc2c..051e49e 100644
--- a/test cases/frameworks/19 pcap/meson.build
+++ b/test cases/frameworks/19 pcap/meson.build
@@ -16,3 +16,7 @@ test('pcaptest', e)
 # Ensure discovery via the configuration tools work also
 pcap_dep = dependency('pcap', version : '>=1.0', method : 'pcap-config')
 pcap_dep = dependency('pcap', version : '>=1.0', method : 'config-tool')
+
+# Check we can apply a version constraint
+dependency('pcap', version: '>=@0@'.format(pcap_dep.version()), method: 'pkg-config', required: false)
+dependency('pcap', version: '>=@0@'.format(pcap_dep.version()), method: 'config-tool')
diff --git a/test cases/frameworks/20 cups/meson.build b/test cases/frameworks/20 cups/meson.build
index 9040de6..d50c4a8 100644
--- a/test cases/frameworks/20 cups/meson.build
+++ b/test cases/frameworks/20 cups/meson.build
@@ -14,3 +14,7 @@ test('cupstest', e)
 # options
 dep = dependency('cups', version : '>=1.4', method : 'cups-config')
 dep = dependency('cups', version : '>=1.4', method : 'config-tool')
+
+# check we can apply a version constraint
+dependency('cups', version: '>=@0@'.format(dep.version()), method: 'pkg-config', required: false)
+dependency('cups', version: '>=@0@'.format(dep.version()), method: 'config-tool')
diff --git a/test cases/frameworks/21 libwmf/meson.build b/test cases/frameworks/21 libwmf/meson.build
index 1fdce2e..ab0ebf6 100644
--- a/test cases/frameworks/21 libwmf/meson.build
+++ b/test cases/frameworks/21 libwmf/meson.build
@@ -17,3 +17,7 @@ test('libwmftest', e)
 
 dependency('libwmf', method : 'config-tool')
 dependency('libwmf', method : 'libwmf-config')
+
+# Check we can apply a version constraint
+dependency('libwmf', version: '>=@0@'.format(libwmf_dep.version()), method: 'pkg-config', required: false)
+dependency('libwmf', version: '>=@0@'.format(libwmf_dep.version()), method: 'config-tool')
diff --git a/test cases/frameworks/4 qt/meson.build b/test cases/frameworks/4 qt/meson.build
index 16fe564..1d7ff4e 100644
--- a/test cases/frameworks/4 qt/meson.build
+++ b/test cases/frameworks/4 qt/meson.build
@@ -103,5 +103,9 @@ foreach qt : ['qt4', 'qt5']
     if qt == 'qt5'
       subdir('subfolder')
     endif
+
+    # Check we can apply a version constraint
+    dependency(qt, modules: qt_modules, version: '>=@0@'.format(qtdep.version()), method : get_option('method'))
+
   endif
 endforeach
diff --git a/test cases/frameworks/9 wxwidgets/meson.build b/test cases/frameworks/9 wxwidgets/meson.build
index d815a2d..0c7ecaa 100644
--- a/test cases/frameworks/9 wxwidgets/meson.build
+++ b/test cases/frameworks/9 wxwidgets/meson.build
@@ -12,4 +12,8 @@ if wxd.found()
   wx_stc = dependency('wxwidgets', version : '>=3.0.0', modules : ['std', 'stc'])
   stc_exe = executable('wxstc', 'wxstc.cpp', dependencies : wx_stc)
   test('wxstctest', stc_exe)
+
+  # Check we can apply a version constraint
+  dependency('wxwidgets', version: '>=@0@'.format(wxd.version()))
+
 endif
diff --git a/test cases/python3/2 extmodule/meson.build b/test cases/python3/2 extmodule/meson.build
index 0ecc813..4916a69 100644
--- a/test cases/python3/2 extmodule/meson.build
+++ b/test cases/python3/2 extmodule/meson.build
@@ -14,6 +14,10 @@ if py3_dep.found()
     py3,
     args : files('blaster.py'),
     env : ['PYTHONPATH=' + pypathdir])
+
+  # Check we can apply a version constraint
+  dependency('python3', version: '>=@0@'.format(py3_dep.version()))
+
 else
   error('MESON_SKIP_TEST: Python3 libraries not found, skipping test.')
 endif