sysconfig: treat MINGW builds as POSIX builds

Co-authored-by: Алексей <[email protected]>

Lib/sysconfig.py

@@ -98,13 +98,18 @@
         },
     }
 
+# GCC[mingw*] use posix build system
+_POSIX_BUILD = os.name == 'posix' or \
+    (os.name == "nt" and 'GCC' in sys.version)
+
 # For the OS-native venv scheme, we essentially provide an alias:
-if os.name == 'nt':
+if os.name == 'nt' and not _POSIX_BUILD:
     _INSTALL_SCHEMES['venv'] = _INSTALL_SCHEMES['nt_venv']
 else:
     _INSTALL_SCHEMES['venv'] = _INSTALL_SCHEMES['posix_venv']
 
 
+
 # NOTE: site.py has copy of this function.
 # Sync it when modify this function.
 def _getuserbase():
@@ -119,7 +124,7 @@ def _getuserbase():
     def joinuser(*args):
         return os.path.expanduser(os.path.join(*args))
 
-    if os.name == "nt":
+    if os.name == "nt" and not _POSIX_BUILD:
         base = os.environ.get("APPDATA") or "~"
         return joinuser(base, "Python")
 
@@ -278,7 +283,7 @@ def _expand_vars(scheme, vars):
 
 
 def _get_preferred_schemes():
-    if os.name == 'nt':
+    if os.name == 'nt' and not _POSIX_BUILD:
         return {
             'prefix': 'nt',
             'home': 'posix_home',
@@ -607,7 +612,7 @@ def parse_config_h(fp, vars=None):
 def get_config_h_filename():
     """Return the path of pyconfig.h."""
     if _PYTHON_BUILD:
-        if os.name == "nt":
+        if os.name == "nt" and not _POSIX_BUILD:
             inc_dir = os.path.join(_PROJECT_BASE, "PC")
         else:
             inc_dir = _PROJECT_BASE
@@ -683,10 +688,10 @@ def get_config_vars(*args):
         except AttributeError:
             _CONFIG_VARS['py_version_nodot_plat'] = ''
 
-        if os.name == 'nt':
+        if os.name == 'nt' and not _POSIX_BUILD:
             _init_non_posix(_CONFIG_VARS)
             _CONFIG_VARS['VPATH'] = sys._vpath
-        if os.name == 'posix':
+        if _POSIX_BUILD:
             _init_posix(_CONFIG_VARS)
         if _HAS_USER_BASE:
             # Setting 'userbase' is done below the call to the
@@ -696,7 +701,7 @@ def get_config_vars(*args):
 
         # Always convert srcdir to an absolute path
         srcdir = _CONFIG_VARS.get('srcdir', _PROJECT_BASE)
-        if os.name == 'posix':
+        if _POSIX_BUILD:
             if _PYTHON_BUILD:
                 # If srcdir is a relative path (typically '.' or '..')
                 # then it should be interpreted relative to the directory