Replace OSError with DistutilsExecError. Fixes pypa/distutils#3 and...

Replace OSError with DistutilsExecError. Fixes pypa/distutils#3 and pypa/setuptools#2228 and bpo-41207.

distutils/spawn.py

@@ -71,9 +71,15 @@ def spawn(cmd, search_path=1, verbose=0, dry_run=0):
             env = dict(os.environ,
                        MACOSX_DEPLOYMENT_TARGET=cur_target)
 
-    proc = subprocess.Popen(cmd, env=env)
-    proc.wait()
-    exitcode = proc.returncode
+    try:
+        proc = subprocess.Popen(cmd, env=env)
+        proc.wait()
+        exitcode = proc.returncode
+    except OSError as exc:
+        if not DEBUG:
+            cmd = cmd[0]
+        raise DistutilsExecError(
+            "command %r failed: %s" % (cmd, exc.args[-1])) from exc
 
     if exitcode:
         if not DEBUG: