NAME
    Devel::TrackSIG - Track those pesky signal handlers

SYNOPSIS
    At the VERY start of your script:

      use Devel::TrackSIG;

    Then, somewhen deep inside the codebase:

      warn "Foo\n"; # WHY DOESN'T THIS GO TO MY SCREEN?

    So you add a debugging line like this:

      print STDERR tied(%SIG)->get_source('__WARN__');
      warn "Foo\n"; # WHY DOESN'T THIS GO TO MY SCREEN?

    Or more comprehensively like this:

      tied(%SIG)->dump_all_sources;
      warn "Foo\n"; # WHY DOESN'T THIS GO TO MY SCREEN?

DESCRIPTION
    Let's face it, signal handlers are a mess. Sometimes, output simply
    disappears into a maze of twisty little handlers all alike and YOU
    CANNOT FIND OUT WHY!

    Well, now you can. Maybe. This module tells you where each and every
    signal handler in effect was set.

    Doing this requires some ugly hacks, so don't leave this in production
    code!

  Import Options
    When loading the module, you can pass any of two named options:

    track_source (default: 1)
      When enabled, all writing %SIG accesses are tracked for later
      reporting.

    report_write_access (default: 0)
      Always shows a stack trace on writing %SIG access.

  get_source
    Given the name of the signal handler you care about, returns the
    backtrace from its origin.

  dump_all_sources
    Dumps all signal handlers origin backtraces to STDERR. Includes those
    signal handlers for which the last access was actually deletion. (Except
    for falling out of scope due to a "local". In this case, we revert to
    the previous backtrace.)

AUTHOR
    Steffen Mueller, "smueller@cpan.org"

ACKNOWLEDGMENT
    This module was originally developed for booking.com. With approval from
    booking.com, this module was generalized and put on CPAN, for which the
    author would like to express his gratitude.

COPYRIGHT AND LICENSE
     (C) 2010-2011 Steffen Mueller. All rights reserved.
 
     This code is available under the same license as Perl version
     5.8.1 or higher.
 
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.