bpo-35516: platform.system_alias() don't replace Darwin (GH-11207)
Add a comment explaining why system_alias() doesn't alias Darwin to
macOS.
diff --git a/Lib/platform.py b/Lib/platform.py
index 9dd3f47..2ab68ae 100755
--- a/Lib/platform.py
+++ b/Lib/platform.py
@@ -514,6 +514,9 @@
# In case one of the other tricks
system = 'Windows'
+ # bpo-35516: Don't replace Darwin with macOS since input release and
+ # version arguments can be different than the currently running version.
+
return system, release, version
### Various internal helpers