test_capi fails on OpenBSD: the allocator fills freed memory with junk

[serhiy-storchaka]

Bug report

test_capi.test_mem.PyMemMallocDebugTests.test_pyobject_freed_is_freed fails on OpenBSD:

AssertionError: object is not seen as freed

The test disables junk filling in the system allocator, so that the pattern written by the debug hooks survives free(), but it only does this for jemalloc (added in gh-90421 for FreeBSD):

    # FreeBSD: instruct jemalloc to not fill freed() memory
    # with junk byte 0x5a, see JEMALLOC(3)
    MALLOC_CONF="junk:false",

OpenBSD has its own allocator, which fills freed memory with junk by default and is configured by MALLOC_OPTIONS, not MALLOC_CONF:

$ env PYTHONMALLOC=malloc_debug MALLOC_CONF="junk:false" ./python -c '...'
AssertionError: object is not seen as freed
$ env PYTHONMALLOC=malloc_debug MALLOC_OPTIONS=j ./python -c '...'
(no error)

Linked PRs

• gh-154502: Disable junk filling in the OpenBSD allocator in test_capi #154503
• [3.15] gh-154502: Disable junk filling in the OpenBSD allocator in test_capi (GH-154503) #154513
• [3.14] gh-154502: Disable junk filling in the OpenBSD allocator in test_capi (GH-154503) #154514
• [3.13] gh-154502: Disable junk filling in the OpenBSD allocator in test_capi (GH-154503) #154515