Assigning os.environ the result of os.environ.copy() replaces it
with a standard dict. This breaks reflection into the actual
environment, as well as features such as case-insensitivity on
Windows, leading to undefined standard library behavior.
R=bryner, gavinmak
Bug: 1511316
Change-Id: I63d026387104ae92669256567854f8bf9d2397a2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5133887
Commit-Queue: Josip Sokcevic <sokcevic@chromium.org>
Reviewed-by: Brian Ryner <bryner@google.com>
Reviewed-by: Gavin Mak <gavinmak@google.com>
Josip Sokcevic