Since d0cdeaab76fef8a6e5a04665df226b6659111e4e (bpo-32554) using random.seed raises DeprecationWarning for some types. This is not handled in test_random causing DeprecationWarnings. I will raise a PR for this.

commit d0cdeaab76fef8a6e5a04665df226b6659111e4e
Author: Raymond Hettinger <rhettinger@users.noreply.github.com>
Date:   Thu Aug 22 09:19:36 2019 -0700

    bpo-32554: Deprecate hashing arbitrary types in random.seed() (GH-15382)

Thanks for doing this.

If you don't mind, let's hold off one day so I can take a closer look at this when I get home tonight.

Sure, I think these were not caught since deprecation warnings are not shown as part of CI as failure. I just caught them at the sprint running with -Wall.

I confirm that test_random currently fails using -Werror:

$ ./python -W error -m test  -v test_random

======================================================================
ERROR: test_seed_when_randomness_source_not_found (test.test_random.MersenneTwister_TestBasicOps)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/vstinner/python/master/Lib/unittest/mock.py", line 1319, in patched
    return func(*newargs, **newkeywargs)
  File "/home/vstinner/python/master/Lib/test/test_random.py", line 60, in test_seed_when_randomness_source_not_found
    self.test_seedargs()
  File "/home/vstinner/python/master/Lib/test/test_random.py", line 46, in test_seedargs
    self.gen.seed(arg)
  File "/home/vstinner/python/master/Lib/random.py", line 156, in seed
    _warn('Seeding based on hashing is deprecated\n'
DeprecationWarning: Seeding based on hashing is deprecated
since Python 3.9 and will be removed in a subsequent version. The only 
supported seed types are: None, int, float, str, bytes, and bytearray.

======================================================================
ERROR: test_seedargs (test.test_random.MersenneTwister_TestBasicOps)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/vstinner/python/master/Lib/test/test_random.py", line 46, in test_seedargs
    self.gen.seed(arg)
  File "/home/vstinner/python/master/Lib/random.py", line 156, in seed
    _warn('Seeding based on hashing is deprecated\n'
DeprecationWarning: Seeding based on hashing is deprecated
since Python 3.9 and will be removed in a subsequent version. The only 
supported seed types are: None, int, float, str, bytes, and bytearray.


I also confirm that PR 15987 fix the issue.

Okay.  This looks good to go.

I don't remember why the original test repeated some of the seeds -- that would normally only be done if caching was present.

New changeset a06d683d7fd88721eaf59abcf5b02eb82045c7b1 by Serhiy Storchaka (Xtreak) in branch 'master':
bpo-38120: Fix DeprecationWarning in test_random for invalid type of arguments to random.seed. (GH-15987)
https://github.com/python/cpython/commit/a06d683d7fd88721eaf59abcf5b02eb82045c7b1