Bug#957675: perl: ftbfs with GCC-10

[Niko Tyni]

Control: tag -1 confirmed

On Fri, Apr 17, 2020 at 11:08:35AM +0000, Matthias Klose wrote:
> Package: src:perl
> Version: 5.30.0-9
> Severity: normal
> Tags: sid bullseye
> User: debian-gcc at lists.debian.org
> Usertags: ftbfs-gcc-10

> The package fails to build in a test rebuild on at least amd64 with
> gcc-10/g++-10, but succeeds to build with gcc-9/g++-9. The
> severity of this report will be raised before the bullseye release,
> so nothing has to be done for the buster release.

> Failed 6 tests out of 2533, 99.76% okay.
> 	../cpan/Memoize/t/tie_gdbm.t
> 	../cpan/Memoize/t/tie_ndbm.t
> 	../ext/GDBM_File/t/gdbm.t
> 	../ext/NDBM_File/t/ndbm.t
> 	../ext/ODBM_File/t/odbm.t
> 	../lib/AnyDBM_File.t

I can reproduce this. It happens at both -O2 and -O0, but goes away when
building with -DDEBUGGING (so our /usr/bin/debugperl).

Backtrace with -O0:

Core was generated by `../../perl -I ../../lib t/gdbm.t'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  __GI___libc_free (mem=0x75cdba2c3b9f9300) at malloc.c:3102
3102    malloc.c: No such file or directory.
(gdb) bt
#0  __GI___libc_free (mem=0x75cdba2c3b9f9300) at malloc.c:3102
#1  0x00007fe03036629a in gdbm_set_errno () from /usr/lib/x86_64-linux-gnu/libgdbm.so.6
#2  0x00007fe030368e17 in gdbm_firstkey () from /usr/lib/x86_64-linux-gnu/libgdbm.so.6
#3  0x00007fe030376cfc in XS_GDBM_File_FIRSTKEY (my_perl=0x55d924b842d0, cv=0x55d9252e20d8) at GDBM_File.c:559
#4  0x000055d924812036 in Perl_pp_entersub (my_perl=0x55d924b842d0) at pp_hot.c:5237
#5  0x000055d9247ff289 in Perl_runops_standard (my_perl=0x55d924b842d0) at run.c:41
#6  0x000055d924700569 in Perl_call_sv (my_perl=0x55d924b842d0, sv=0x55d9252f9668, flags=4098) at perl.c:3026
#7  0x000055d9247da427 in Perl_magic_methcall (my_perl=0x55d924b842d0, sv=0x55d924bce860, mg=0x55d925316cf0, 
    meth=0x55d9252f9668, flags=0, argc=0) at mg.c:1942
#8  0x000055d9247dac78 in Perl_magic_nextpack (my_perl=0x55d924b842d0, sv=0x55d924bce860, mg=0x55d925316cf0, 
    key=0x55d9252f92c0) at mg.c:2078
#9  0x000055d9247fa581 in Perl_hv_iternext_flags (my_perl=0x55d924b842d0, hv=0x55d924bce860, flags=0)
    at hv.c:2722
#10 0x000055d924859e27 in Perl_pp_each (my_perl=0x55d924b842d0) at pp.c:5049
#11 0x000055d9247ff289 in Perl_runops_standard (my_perl=0x55d924b842d0) at run.c:41
#12 0x000055d9246ffc9c in S_run_body (my_perl=0x55d924b842d0, oldscope=1) at perl.c:2716
#13 0x000055d9246ff69b in perl_run (my_perl=0x55d924b842d0) at perl.c:2639
#14 0x000055d9246c7226 in main (argc=4, argv=0x7fffb8604158, env=0x7fffb8604180) at perlmain.c:127

I'll look into this more later.
-- 
Niko Tyni   ntyni at debian.org