Issue #27048: Prevents distutils failing on Windows when environment variables contain non-ASCII characters

Lib/distutils/_msvccompiler.py

@@ -86,11 +86,9 @@ def _get_vc_env(plat_spec):
 
     try:
         out = subprocess.check_output(
-            '"{}" {} && set'.format(vcvarsall, plat_spec),
-            shell=True,
+            'cmd /u /c "{}" {} && set'.format(vcvarsall, plat_spec),
             stderr=subprocess.STDOUT,
-            universal_newlines=True,
-        )
+        ).decode('utf-16le', errors='replace')
     except subprocess.CalledProcessError as exc:
         log.error(exc.output)
         raise DistutilsPlatformError("Error executing {}"

Lib/distutils/tests/test_msvccompiler.py

@@ -83,6 +83,24 @@ class msvccompilerTestCase(support.TempdirManager,
         self.assertFalse(os.path.isfile(os.path.join(
             tempdir, os.path.basename(dll))))
 
+    def test_get_vc_env_unicode(self):
+        import distutils._msvccompiler as _msvccompiler
+
+        test_var = 'ṰḖṤṪ┅ṼẨṜ'
+        test_value = '₃⁴₅'
+
+        # Ensure we don't early exit from _get_vc_env
+        old_distutils_use_sdk = os.environ.pop('DISTUTILS_USE_SDK', None)
+        os.environ[test_var] = test_value
+        try:
+            env = _msvccompiler._get_vc_env('x86')
+            self.assertIn(test_var.lower(), env)
+            self.assertEqual(test_value, env[test_var.lower()])
+        finally:
+            os.environ.pop(test_var)
+            if old_distutils_use_sdk:
+                os.environ['DISTUTILS_USE_SDK'] = old_distutils_use_sdk
+
 def test_suite():
     return unittest.makeSuite(msvccompilerTestCase)
 

Misc/NEWS

@@ -10,6 +10,9 @@ What's New in Python 3.6.0 alpha 3
 Library
 -------
 
+- Issue #27048: Prevents distutils failing on Windows when environment
+  variables contain non-ASCII characters
+
 - Issue #27330: Fixed possible leaks in the ctypes module.
 
 - Issue #27238: Got rid of bare excepts in the turtle module.  Original patch