I am seeing some weird behavior where Devel::Cover seems to be removing/consuming information I am trying to extract with caller(). I have managed to isolate the behavior in a small script, which is included below. Anyone else seen this problem before?

Here is the script: 

#!/usr/bin/perl

use strict;
use warnings;

use Test::More tests => 2;

{
    package TestCaller;

    use strict;
    use warnings;

    sub throw {
        my $self = bless {}, __PACKAGE__;
        my $i = 0;
        my @stack_trace;
        push @stack_trace, [ (caller($i))[0 .. 3] ] while caller(++$i)
+;        
        $self->{stack_trace} = \@stack_trace;
        die $self;
    }
}

eval { throw TestCaller };
isa_ok($@, 'TestCaller');

is_deeply($@->{stack_trace},
          [[ 'main', 'test.pl', 24, '(eval)']],
          '... got the stack trace we expected');
1;

[download]
And here is the output of that script 

[:~] stevan% perl test.pl
1..2
ok 1 - The object isa TestCaller
ok 2 - ... got the stack trace we expected
[:~] stevan% perl -MDevel::Cover test.pl
1..2
Devel::Cover 0.47: Collecting coverage data for branch, condition, pod
+, statement, subroutine and time.
Selecting packages matching:
Ignoring packages matching:
    /Devel/Cover[./]
Ignoring packages in:
    .
    /Library/Perl
    /Library/Perl/darwin
    /Users/stevan/Projects/PerlFramework
ok 1 - The object isa TestCaller
not ok 2 - ... got the stack trace we expected
#     Failed test (test.pl at line 27)
#     Structures begin differing at:
#          $got->[0][0] = Does not exist
#     $expected->[0][0] = 'main'
# Looks like you failed 1 tests of 2.
Devel::Cover: Writing coverage database to /Users/stevan/cover_db/runs
+/1094834470.5906.15059
---------------------------- ------ ------ ------ ------ ------ ------
+ ------
File                           stmt branch   cond    sub    pod   time
+  total
---------------------------- ------ ------ ------ ------ ------ ------
+ ------
test.pl                       100.0    n/a    n/a  100.0    n/a  100.0
+  100.0
Total                         100.0    n/a    n/a  100.0    n/a  100.0
+  100.0
---------------------------- ------ ------ ------ ------ ------ ------
+ ------

[download]
Am I doing something wrong? Or is this a limitation of Devel::Cover? Any thoughts? Does this have something to do with Devel::Cover's use of the runops function maybe?

I have asked this over at the perl-qa list as well, but I thought it would be useful to ask it here too.

-stvn

In reply to Devel::Cover eating caller() information by stvn

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