LFS 8.3 Glibc-2.28 make check fail 'stdlib/test-bz22786'

Question

I am on Section 6.9 of the LFS book, My host OS is Ubuntu 18.04, When I ran make check I got errors as follow:

    UNSUPPORTED: elf/tst-audit10
    UNSUPPORTED: elf/tst-avx512
    XPASS: elf/tst-protected1a
    XPASS: elf/tst-protected1b
    FAIL: inet/tst-idna_name_classify
    UNSUPPORTED: math/test-double-libmvec-alias-avx512
    UNSUPPORTED: math/test-double-libmvec-alias-avx512-main
    UNSUPPORTED: math/test-double-libmvec-sincos-avx512
    UNSUPPORTED: math/test-float-libmvec-alias-avx512
    UNSUPPORTED: math/test-float-libmvec-alias-avx512-main
    UNSUPPORTED: math/test-float-libmvec-sincosf-avx512
    UNSUPPORTED: misc/tst-pkey
    FAIL: misc/tst-ttyname
    UNSUPPORTED: nptl/test-cond-printers
    UNSUPPORTED: nptl/test-condattr-printers
    UNSUPPORTED: nptl/test-mutex-printers
    UNSUPPORTED: nptl/test-mutexattr-printers
    UNSUPPORTED: nptl/test-rwlock-printers
    UNSUPPORTED: nptl/test-rwlockattr-printers
    UNSUPPORTED: posix/tst-sysconf-empty-chroot
    UNSUPPORTED: resolv/tst-resolv-ai_idn
    UNSUPPORTED: resolv/tst-resolv-ai_idn-latin1
    FAIL: stdlib/test-bz22786
    Summary of test results:
          3 FAIL
       5836 PASS
         18 UNSUPPORTED
         17 XFAIL
          2 XPASS
    make[1]: *** [Makefile:347: tests] Error 1
    make[1]: Leaving directory '/sources/glibc-2.28'
    make: *** [Makefile:9: check] Error 2

I want know the error stdlib/test-bz22786 is a harmless message or not?

Answer 1

The old version of stdlib/test-bz22786 needed more than 2 GiB of RAM to complete successfully. If your system does not have that much RAM and uses swap space instead, the test will execute very slowly and eventually time out, leading to the test failure you see.

This is fixed on the release/2.28/master upstream branch, by backporting this upstream commit which uses alias mappings for memory compression. The backport needs some further patches, which are also on the branch. It's usually a good idea to track the release branch (except that a commit broke malloc earlier this week, so perhaps now is not a good time to start).

Thanks for paying attention to glibc test results.