WIP: Debug ResourceWarnings BufferedRandom

[mroeschke]

xref #44844

[twoertwein]

might be good to have a test whether lsof finds ResourceWarnings (the psutil doesn't seem to find them/some of them).

with pytest.raises(...):
    with check_bufferedrandom_resourcewarning():
        foo = open("foo")
foo.close()

Specifically enabling ResourceWarnings (usually disabled by default) seemed to work well for me in #39047: adding always::ResourceWarning to filterwarnings in setup.cfg.

[jbrockmendel]

maybe just enable for pandas.tests.io?

[mroeschke]

might be good to have a test whether lsof finds ResourceWarnings (the psutil doesn't seem to find them/some of them).

with pytest.raises(...):
    with check_bufferedrandom_resourcewarning():
        foo = open("foo")
foo.close()

Specifically enabling ResourceWarnings (usually disabled by default) seemed to work well for me in #39047: adding always::ResourceWarning to filterwarnings in setup.cfg.

Yeah might do this in a follow up. Ideally just checking which tests open up new OS-level file handles. Apparently the BufferedResourceWarning opens it up at n=10

[mroeschke]

Closing in favor of #45073