Just preparing to make a refleaks test run, so I ran:

./python -m test --help

The output related to refleaks seemed suspicious:

...
Special runs:
  -l, --findleaks       deprecated alias to --fail-env-changed
...
  --fail-env-changed    if a test file alters the environment, mark the test as failed

It's not obvious that "--fail-env-changed" has anything to do with "--findleaks". Does the -l/--findleaks message need to be corrected?

IIUC you're looking for --huntrleaks/-R, not the unrelated --findleaks/-l:

In that -m test -h menu:

  -l, --findleaks       deprecated alias to --fail-env-changed

  -R RUNCOUNTS, --huntrleaks RUNCOUNTS
                        search for reference leaks (needs debug build, very slow). See the section at bottom
                        for more details.

Thanks, I get that. My issue is with the apparent mismatch between the English meaning of "find leaks" and "fail env changed." It seems to me that the help message(s) for one or both of those options is probably incorrect and needs to be changed.

That's probably why --findleaks was deprecated (in 3.8, PR12951).  We could remove it now. 

+ vstinner

In Python 3.6, regrtest failed if --findleaks was used and gc.garbage was not empty after a test completed.

I modified regrtest to always run this check: --findleaks is now ignored.

But I also modified --findleaks to make it an alias to the --fail-env-changed option: non-zero exit code if a test fails with "ENV CHANGED" status.

I wrote PR 29514 to clarify the situation: remove --findleaks :-)

To check for reference leaks, memory leaks and file descriptor leaks: --huntrleaks/-R should be used.

New changeset 9d3271438431c37c29c359f5b73e8094b5f82912 by Victor Stinner in branch 'main':
bpo-45745: Remove regrtest --findleaks options (GH-29514)
https://github.com/python/cpython/commit/9d3271438431c37c29c359f5b73e8094b5f82912