Bug #69236 for Any-Moose:

Using a lazy attribute builder with threads causes invalid memory accesses. For example, if you run this code with valgrind: -------- package Foo; use Any::Moose; has 'max' => (isa => 'Int', is => 'ro', lazy => 1, builder => '_build_max'); sub _build_max { return 42; } package main; use threads; my $foo = Foo->new; threads->create(sub { print $foo->max; })->join; -------- you get: ==14648== 42==14648== Invalid read of size 4 ==14648== at 0x4EE3289: Perl_sv_free (sv.c:5631) ==14648== by 0x4ED246F: Perl_av_undef (av.c:495) ==14648== by 0x4EE2F37: Perl_sv_clear (sv.c:5507) ==14648== by 0x4EE3211: Perl_sv_free2 (sv.c:5694) ==14648== by 0x4EC346A: Perl_mg_free (mg.c:529) ==14648== by 0x4EE2CD7: Perl_sv_clear (sv.c:5470) ==14648== by 0x4EE3211: Perl_sv_free2 (sv.c:5694) ==14648== by 0x4E7EDED: Perl_gp_free (gv.c:1600) ==14648== by 0x4EE30C4: Perl_sv_clear (sv.c:5522) ==14648== by 0x4EE3211: Perl_sv_free2 (sv.c:5694) ==14648== by 0x4EDC630: S_visit (sv.c:441) ==14648== by 0x4EDCB9A: Perl_sv_clean_all (sv.c:588) ==14648== Address 0x6f9c6a8 is 3,560 bytes inside a block of size 4,080 free'd ==14648== at 0x4C282ED: free (vg_replace_malloc.c:366) ==14648== by 0x4EDCBFA: Perl_sv_free_arenas (sv.c:655) ==14648== by 0x4E7A6BD: perl_destruct (perl.c:1338) ==14648== by 0x6FFC246: S_ithread_clear (threads.xs:166) ==14648== by 0x6FFE1EA: XS_threads_join (threads.xs:1154) ==14648== by 0x4EDB264: Perl_pp_entersub (pp_hot.c:2891) ==14648== by 0x4ED2CCF: Perl_runops_standard (run.c:40) ==14648== by 0x4E7E5FD: perl_run (perl.c:2431) ==14648== by 0x400CCB: main (perlmain.c:117) ==14648== ==14648== Invalid read of size 4 ==14648== at 0x4EE3290: Perl_sv_free (sv.c:5632) ==14648== by 0x4ED246F: Perl_av_undef (av.c:495) ==14648== by 0x4EE2F37: Perl_sv_clear (sv.c:5507) ==14648== by 0x4EE3211: Perl_sv_free2 (sv.c:5694) ==14648== by 0x4EC346A: Perl_mg_free (mg.c:529) ==14648== by 0x4EE2CD7: Perl_sv_clear (sv.c:5470) ==14648== by 0x4EE3211: Perl_sv_free2 (sv.c:5694) ==14648== by 0x4E7EDED: Perl_gp_free (gv.c:1600) ==14648== by 0x4EE30C4: Perl_sv_clear (sv.c:5522) ==14648== by 0x4EE3211: Perl_sv_free2 (sv.c:5694) ==14648== by 0x4EDC630: S_visit (sv.c:441) ==14648== by 0x4EDCB9A: Perl_sv_clean_all (sv.c:588) ==14648== Address 0x6f9c6ac is 3,564 bytes inside a block of size 4,080 free'd ==14648== at 0x4C282ED: free (vg_replace_malloc.c:366) ==14648== by 0x4EDCBFA: Perl_sv_free_arenas (sv.c:655) ==14648== by 0x4E7A6BD: perl_destruct (perl.c:1338) ==14648== by 0x6FFC246: S_ithread_clear (threads.xs:166) ==14648== by 0x6FFE1EA: XS_threads_join (threads.xs:1154) ==14648== by 0x4EDB264: Perl_pp_entersub (pp_hot.c:2891) ==14648== by 0x4ED2CCF: Perl_runops_standard (run.c:40) ==14648== by 0x4E7E5FD: perl_run (perl.c:2431) ==14648== by 0x400CCB: main (perlmain.c:117) ==14648== ==14648== ==14648== HEAP SUMMARY: ==14648== in use at exit: 9,621 bytes in 56 blocks ==14648== total heap usage: 50,298 allocs, 50,242 frees, 4,625,064 bytes allocated ==14648== ==14648== LEAK SUMMARY: ==14648== definitely lost: 3,872 bytes in 35 blocks ==14648== indirectly lost: 0 bytes in 0 blocks ==14648== possibly lost: 0 bytes in 0 blocks ==14648== still reachable: 5,749 bytes in 21 blocks ==14648== suppressed: 0 bytes in 0 blocks ==14648== Rerun with --leak-check=full to see details of leaked memory Interestingly, if 'use Any::Moose;' is changed to 'use Moose;', it works fine.