I ran "python -m test" on an up to date master branch (commit fe52eb62191e640e720d184a9a1a04e965b8a062), there is a single remaining issue. test_distutils failed because the deprecation warning was already emited: issue fixed by PR 25675. The other issues are gone.

Shreyan Avigyan: "Same errors."

IMO it's a mistake on your side. You ran an outdated version or you didn't rebuild Python cleanly.

"FYI test_signal is no longer modifying sys.gettrace thanks to your fix. But test_threading still does. (...) I ran the test again and test_signal still modifies sys.gettrace()"

It's not my case on my machine, again it sounds like an issue on your side.