PerlOnTheWay has asked for the wisdom of the Perl Monks concerning the following question:

It can't be reproduced easily,as it's running a huge lot of stuff before this problem occurs(but it happens each time at this point)

Anyone else has ever met this kind of problem while debugging with Apache::DB? 

0  J::Exception=HASH(0x7f268ece7d40)
   'frames' => ARRAY(0x7f268ece7e00)
      0  Devel::StackTraceFrame=HASH(0x7f268914fb80)
         'args' => ARRAY(0x7f268914f420)
            0  'Bizarre copy of ARRAY in sassign at /usr/lib64/perl5/s
+ite_perl/5.8.8/x86_64-linux-thread-multi/Apache/perl5db.pl line 3731
'
         'bitmask' => "UUUUUUUUUUUUUU\cA"
         'evaltext' => undef
         'filename' => '/*****/lib/J/Home/Element/Base.pm'
         'hasargs' => 1
         'hints' => 2
         'is_require' => undef
         'line' => 36
         'package' => 'J::Home::Element::Base'
         'respect_overload' => 1
         'subroutine' => 'Carp::croak'
         'wantarray' => undef
      1  Devel::StackTraceFrame=HASH(0x7f268914f040)
         'args' => ARRAY(0x7f268914f6c0)
            0  'J::Home::Element::Ad::AudienceScience=HASH(0x7f268ecd1
+b70)'
            1  'J::Template::_user::pc=HASH(0x7f268e06fb30)'
         'bitmask' => "UUUUUUUUUUUUUU\cA"
         'evaltext' => undef
         'filename' => '/*****/lib/J/Home/Controller.pm'
         'hasargs' => 1
         'hints' => 2
         'is_require' => undef
         'line' => 220
         'package' => 'J::Home::Controller'
         'respect_overload' => 1
         'subroutine' => 'J::Home::Element::Base::try_render'
         'wantarray' => undef
      2  Devel::StackTraceFrame=HASH(0x7f268914fbb0)
         'args' => ARRAY(0x7f268914fe20)
            0  'J::Home::Controller'
         'bitmask' => "UUUUUUUUUUUUUU\cA"
         'evaltext' => undef
         'filename' => '/*****/home.pl'
         'hasargs' => 1
         'hints' => 2
         'is_require' => undef
         'line' => 5
         'package' => 'ModPerl::ROOT::ModPerl::Registry::*****_home
+_2epl'
         'respect_overload' => 1
         'subroutine' => 'J::Pages::display'
         'wantarray' => undef
   'message' => 'Bizarre copy of ARRAY in sassign'
   'with_pages' => 1

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Re: Bizarre copy of ARRAY in sassign at /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/Apache/perl5db.pl line 3731
by dave_the_m (Monsignor) on Aug 22, 2011 at 15:13 UTC
    You normally get this sort of error if you're printing a stack backtrack including function args, and one one of the args has been freed and since re-allocated (this can happen because the perl stack isn't reference counted, which is a long-standing bug).

    So something like the following (which doesn't reproduce the error in this case, but gives you an idea of what can happen): 

    use Carp;
@a = (1,2);
foo(@a);
sub foo {
    @a = ();
    Carp::cluck();
}

    [download]
    Dave.
[reply]
[d/l]
      Is there any work around to this kind of issue?
[reply]
        is there any work around to this kind of issue?
        Well in general terms, avoid freeing anything that's still in use as a function argument, or avoid dumping function arguments on error.

        Dave.

[reply]
Re: Bizarre copy of ARRAY in sassign at /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/Apache/perl5db.pl line 3731
by ikegami (Patriarch) on Aug 22, 2011 at 17:28 UTC
    I believe it also happens if an AV (array) is put on the stack. This would be caused by a bug in Perl or in an XS module.
[reply]

      It turns out to be caused by Net::IP::Match::XS::match_ip

      Is it a known issue that this module is not compatible with Apache::DB?

      update

      I was wrong,it still happens after I comment that line out, looks like a wild pointer problem in C,is there any wat to diagnose this issue?

      update2

      Looks like it's in-compatible with Apache2::RequestUtil->request

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[d/l]
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Re: Bizarre copy of ARRAY in sassign at /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/Apache/perl5db.pl line 3731
by Sewi (Friar) on Nov 12, 2011 at 11:06 UTC
[reply]

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