From 360aadc4c2a9941a68a3f3f63375ce5380fef6a0 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sat, 11 Jul 2020 15:31:18 -0400
Subject: [PATCH 1/2] Allow spawn to accept environment. Avoid monkey-patching
 global state. Closes pypa/setuptools#2212 and closes pypa/distutils#5.

---
 distutils/_msvccompiler.py | 8 ++------
 distutils/spawn.py         | 8 ++++----
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/distutils/_msvccompiler.py b/distutils/_msvccompiler.py
index af8099a407..0e98692e31 100644
--- a/distutils/_msvccompiler.py
+++ b/distutils/_msvccompiler.py
@@ -501,12 +501,8 @@ def link(self,
             log.debug("skipping %s (up-to-date)", output_filename)
 
     def spawn(self, cmd):
-        old_path = os.getenv('path')
-        try:
-            os.environ['path'] = self._paths
-            return super().spawn(cmd)
-        finally:
-            os.environ['path'] = old_path
+        env = dict(os.environ, path=self._paths)
+        return super().spawn(cmd, env=env)
 
     # -- Miscellaneous methods -----------------------------------------
     # These are all used by the 'gen_lib_options() function, in
diff --git a/distutils/spawn.py b/distutils/spawn.py
index 0d1bd0391e..fc592d4a91 100644
--- a/distutils/spawn.py
+++ b/distutils/spawn.py
@@ -20,7 +20,7 @@
     _cfg_target_split = None
 
 
-def spawn(cmd, search_path=1, verbose=0, dry_run=0):
+def spawn(cmd, search_path=1, verbose=0, dry_run=0, env=None):
     """Run another program, specified as a command list 'cmd', in a new process.
 
     'cmd' is just the argument list for the new process, ie.
@@ -49,7 +49,8 @@ def spawn(cmd, search_path=1, verbose=0, dry_run=0):
         if executable is not None:
             cmd[0] = executable
 
-    env = None
+    env = env if env is not None else dict(os.environ)
+
     if sys.platform == 'darwin':
         global _cfg_target, _cfg_target_split
         if _cfg_target is None:
@@ -68,8 +69,7 @@ def spawn(cmd, search_path=1, verbose=0, dry_run=0):
                           'now "%s" but "%s" during configure'
                                 % (cur_target, _cfg_target))
                 raise DistutilsPlatformError(my_msg)
-            env = dict(os.environ,
-                       MACOSX_DEPLOYMENT_TARGET=cur_target)
+            env.update(MACOSX_DEPLOYMENT_TARGET=cur_target)
 
     try:
         proc = subprocess.Popen(cmd, env=env)

From 8a4bc38e7b582b2006e17118162b1d2a0a23b8ad Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 12 Jul 2020 05:02:18 -0400
Subject: [PATCH 2/2] Update changelog.

---
 changelog.d/2212.misc.rst | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/2212.misc.rst

diff --git a/changelog.d/2212.misc.rst b/changelog.d/2212.misc.rst
new file mode 100644
index 0000000000..d6fc7bf8af
--- /dev/null
+++ b/changelog.d/2212.misc.rst
@@ -0,0 +1 @@
+(Distutils) Allow spawn to accept environment. Avoid monkey-patching global state.