andreasgudmundsson / p5-devel-unwind Goto Github PK

On all the versions perlbrew gives me after 5.18.4 (the earliest of which is 5.20.3), the following script exits with a segfault:

use v5.12;
use Devel::Unwind;

say $^V;
$SIG{__DIE__} = sub { say "oh no" };

alarm 1;

mark HI {
    local $SIG{ALRM} = sub {
        local $SIG{__DIE__};
        unwind HI "BYE";
    };

    sleep 3;
};

$@ and say $@;

A log of the runs with the various perls:
segfault_signal_run.txt

I originally thought this was the same as #3 but it turns out it affects different perl versions so I'm no longer so certain. The following gives segfaults on all my perl versions >= 5.24.0:

use v5.12;
use Devel::Unwind;

say $^V;
$SIG{__DIE__} = sub { say "oh no" };

mark HI {
    eval {
        local $SIG{__DIE__};
        unwind HI "BYE";
    };
};

$@ and say $@;

Log file:
segfault_run.txt

Note that if you remove the local $SIG{__DIE__}, something slightly different happens:

perl-5.22.3
==========
v5.22.3
oh no
BYE at segfault.pl line 11.


perl-5.24.1
==========
v5.24.1
oh no
BYE at segfault.pl line 10.

perl begins to report the unwinding starting from the beginning of the eval BLOCK rather than from the unwind call.