Bug#628493: perl: FTBFS on kfreebsd-i386: t/op/threads failed

[Niko Tyni]

On Sun, May 29, 2011 at 04:01:48PM +0100, Dominic Hargreaves wrote:
> Source: perl
> Version: 5.14.0-1
> Severity: important
> 
> perl 5.14 failed to build on kfreebsd-i386:
> 
> <https://buildd.debian.org/status/fetch.php?pkg=perl&arch=kfreebsd-i386&ver=5.14.0-1&stamp=1306233511>
> 
> t/op/threads...................................................FAILED--expected 24 tests, saw 23

I'm able to reproduce this on a kvm kfreebsd-i386 virtual machine with
SMP enabled (but not on a non-SMP kernel, where the package builds fine.)

 ./perl.debug -Ilib -Mthreads -e 'threads->create(sub {})->detach; open(my $out, "|$^X") or die $!'; 

crashes non-deterministically more than half of the time for me
(and hangs about 10% of the time.)

The next thing is to try and reproduce it on bleadperl. 

FWIW, the relevant test was introduced as part of the fix for [perl #78494].

Stack trace:

  Core was generated by `perl.debug'.
  Program terminated with signal 11, Segmentation fault.
  #0  0x283a8062 in nanosleep () from /lib/i386-kfreebsd-gnu/i686/cmov/libpthread.so.0
  (gdb) bt
  #0  0x283a8062 in nanosleep () from /lib/i386-kfreebsd-gnu/i686/cmov/libpthread.so.0
  #1  0x283a6358 in T.25 () from /lib/i386-kfreebsd-gnu/i686/cmov/libpthread.so.0
  #2  0x283a64ce in __pthread_alt_unlock () from /lib/i386-kfreebsd-gnu/i686/cmov/libpthread.so.0
  #3  0x283a385f in pthread_mutex_unlock () from /lib/i386-kfreebsd-gnu/i686/cmov/libpthread.so.0
  #4  0x08110f9f in Perl_atfork_unlock () at util.c:2884
  #5  0x283a3b86 in __pthread_fork () from /lib/i386-kfreebsd-gnu/i686/cmov/libpthread.so.0
  #6  0x28445bd1 in fork () from /lib/i386-kfreebsd-gnu/i686/cmov/libc.so.0.1
  #7  0x283a3ab4 in fork () from /lib/i386-kfreebsd-gnu/i686/cmov/libpthread.so.0
  #8  0x081114df in Perl_my_fork (my_perl=0x8350f60, cmd=0x83eef85 "/home/niko/perl/perl.debug", 
      mode=0xbfbfe574 "w") at util.c:2900
  #9  Perl_my_popen (my_perl=0x8350f60, cmd=0x83eef85 "/home/niko/perl/perl.debug", mode=0xbfbfe574 "w")
      at util.c:2695
  #10 0x082203f7 in Perl_do_openn (my_perl=0x8350f60, gv=0x83547b8, 
      oname=0x83eef54 "|/home/niko/perl/perl.debug", len=<value optimized out>, as_raw=0, rawmode=0, 
      rawperm=0, supplied_fp=0x0, svp=0x83565a8, num_svs=0) at doio.c:274
  #11 0x081fa8da in Perl_pp_open (my_perl=0x8350f60) at pp_sys.c:604
  #12 0x0810c58f in Perl_runops_debug (my_perl=0x8350f60) at dump.c:2266
  #13 0x0808d2dd in S_run_body (my_perl=0x8350f60) at perl.c:2350
  #14 perl_run (my_perl=0x8350f60) at perl.c:2268
  #15 0x08061837 in main (argc=5, argv=0xbfbfe788, env=0xbfbfe7a0) at perlmain.c:120
 
-- 
Niko Tyni   ntyni at debian.org