environment: provide a more detailed explanation of linker detection failures

Just saying "it failed" is accurate, but not useful to helping someone
figure out why it failed. Giving them the stdout and stderr (like we
might with compilers) should help people resolve the issue.

Fixes: #7173

1 files changed, 8 insertions, 2 deletions

diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index b9505b6..33cc3a5 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -964,6 +964,12 @@ class Environment:
                 errmsg += '\nRunning "{0}" gave "{1}"'.format(c, e)
         raise EnvironmentException(errmsg)
 
+    @staticmethod
+    def __failed_to_detect_linker(compiler: T.List[str], args: T.List[str], stdout: str, stderr: str) -> 'T.NoReturn':
+        msg = 'Unable to detect linker for compiler "{} {}"\nstdout: {}\nstderr: {}'.format(
+            ' '.join(compiler), ' '.join(args), stdout, stderr)
+        raise EnvironmentException(msg)
+
     def _guess_win_linker(self, compiler: T.List[str], comp_class: Compiler,
                           for_machine: MachineChoice, *,
                           use_linker_prefix: bool = True, invoked_directly: bool = True,
@@ -1026,7 +1032,7 @@ class Environment:
                 "Found GNU link.exe instead of MSVC link.exe. This link.exe "
                 "is not a linker. You may need to reorder entries to your "
                 "%PATH% variable to resolve this.")
-        raise EnvironmentException('Unable to determine dynamic linker')
+        self.__failed_to_detect_linker(compiler, check_args, o, e)
 
     def _guess_nix_linker(self, compiler: T.List[str], comp_class: T.Type[Compiler],
                           for_machine: MachineChoice, *,
@@ -1117,7 +1123,7 @@ class Environment:
                 compiler, for_machine, comp_class.LINKER_PREFIX, override,
                 version=search_version(e))
         else:
-            raise EnvironmentException('Unable to determine dynamic linker')
+            self.__failed_to_detect_linker(compiler, check_args, o, e)
         return linker
 
     def _detect_c_or_cpp_compiler(self, lang: str, for_machine: MachineChoice) -> Compiler: