[Catalyst] Stack tracing exceptions

[Matt S Trout]

On Fri, Dec 09, 2005 at 08:02:00AM -0600, Brandon Black wrote:
> The bigger issue, IMHO, is that exceptions provide no stack trace.

Try applying the following patch to trunk and see how you go. It manages
the stack trace part, but the trace is maybe a little verbose as yet (hence
why it's a patch rather than a commit). An example stack trace follows the
patch.

=== lib/Catalyst.pm
==================================================================
--- lib/Catalyst.pm     (revision 4486)
+++ lib/Catalyst.pm     (local)
@@ -18,6 +18,7 @@
 use URI;
 use Scalar::Util qw/weaken/;
 use attributes;
+use Carp ();

 __PACKAGE__->mk_accessors(
     qw/counter request response state action stack namespace/
@@ -1094,6 +1095,12 @@
 sub handle_request {
     my ( $class, @arguments ) = @_;

+    local $SIG{__DIE__} =
+        sub {
+            return if $_[0] eq $Catalyst::DETACH;
+            die Carp::longmess(@_);
+        };
+
     # Always expect worst case!
     my $status = -1;
     eval {
####################### END OF PATCH

####################### SAMPLE STACK TRACE
Caught exception in TestApp::Controller::Engine::Response::Errors->one "Illegal division by zero at /usr/home/matthewt/wdir/Catalyst/trunk/Catalyst/t/lib/TestApp/Controller/Engine/Response/Errors.pm line 10.
 at /usr/home/matthewt/wdir/Catalyst/trunk/Catalyst/t/lib/TestApp/Controller/Engine/Response/Errors.pm line 10
        TestApp::Controller::Engine::Response::Errors::one('TestApp::Controller::Engine::Response::Errors=HASH(0x86dbfbc)'
'TestApp=HASH(0x8855174)') called at lib/Catalyst.pm line 917
        eval {...} called at lib/Catalyst.pm line 917
        Catalyst::execute('TestApp=HASH(0x8855174)'
'TestApp::Controller::Engine::Response::Errors'
'Catalyst::Action=HASH(0x87768d4)') called at /usr/home/matthewt/wdir/Catalyst/trunk/Catalyst/t/lib/TestApp.pm line 50
        TestApp::execute('TestApp=HASH(0x8855174)'
'TestApp::Controller::Engine::Response::Errors'
'Catalyst::Action=HASH(0x87768d4)') called at lib/Catalyst/Action.pm line 43
        Catalyst::Action::execute('Catalyst::Action=HASH(0x87768d4)'
'TestApp=HASH(0x8855174)') called at lib/Catalyst/Base.pm line 46
        Catalyst::Base::_ACTION('TestApp::Controller::Engine::Response::Errors=HASH(0x86dbfbc)'
'TestApp=HASH(0x8855174)') called at lib/Catalyst.pm line 917
        eval {...} called at lib/Catalyst.pm line 917
        Catalyst::execute('TestApp=HASH(0x8855174)'
'TestApp::Controller::Engine::Response::Errors'
'Catalyst::Action=HASH(0x8776f70)') called at /usr/home/matthewt/wdir/Catalyst/trunk/Catalyst/t/lib/TestApp.pm line 50
        TestApp::execute('TestApp=HASH(0x8855174)'
'TestApp::Controller::Engine::Response::Errors'
'Catalyst::Action=HASH(0x8776f70)') called at lib/Catalyst/Action.pm line 43
        Catalyst::Action::execute('Catalyst::Action=HASH(0x8776f70)'
'TestApp=HASH(0x8855174)') called at lib/Catalyst/Dispatcher.pm line 164
        Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x854b14c)'
'TestApp=HASH(0x8855174)'
'_ACTION') called at lib/Catalyst.pm line 253
        Catalyst::forward('TestApp=HASH(0x8855174)'
'_ACTION') called at lib/Catalyst/Base.pm line 20
        Catalyst::Base::_DISPATCH('TestApp::Controller::Engine::Response::Errors=HASH(0x86dbfbc)'
'TestApp=HASH(0x8855174)') called at lib/Catalyst.pm line 917
        eval {...} called at lib/Catalyst.pm line 917
        Catalyst::execute('TestApp=HASH(0x8855174)'
'TestApp::Controller::Engine::Response::Errors'
'Catalyst::Action=HASH(0x8777180)') called at /usr/home/matthewt/wdir/Catalyst/trunk/Catalyst/t/lib/TestApp.pm line 50
        TestApp::execute('TestApp=HASH(0x8855174)'
'TestApp::Controller::Engine::Response::Errors'
'Catalyst::Action=HASH(0x8777180)') called at lib/Catalyst/Action.pm line 43
        Catalyst::Action::execute('Catalyst::Action=HASH(0x8777180)'
'TestApp=HASH(0x8855174)') called at lib/Catalyst/Dispatcher.pm line 164
        Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x854b14c)'
'TestApp=HASH(0x8855174)'
'/engine/response/errors/_DISPATCH') called at lib/Catalyst.pm line 253
        Catalyst::forward('TestApp=HASH(0x8855174)'
'/engine/response/errors/_DISPATCH') called at lib/Catalyst/Dispatcher.pm line 57
        Catalyst::Dispatcher::dispatch('Catalyst::Dispatcher=HASH(0x854b14c)'
'TestApp=HASH(0x8855174)') called at lib/Catalyst.pm line 858
        Catalyst::dispatch('TestApp=HASH(0x8855174)') called at lib/Catalyst.pm line 1112
        Catalyst::__ANON__ called at lib/Catalyst.pm line 1129
        eval {...} called at lib/Catalyst.pm line 1106
        Catalyst::handle_request('TestApp') called at lib/Catalyst/Test.pm line 104
        Catalyst::Test::local_request('TestApp'
'http://localhost/engine/response/errors/one') called at lib/Catalyst/Test.pm line 82
        Catalyst::Test::__ANON__('http://localhost/engine/response/errors/one') 

-- 
     Matt S Trout       Offering custom development, consultancy and support
  Technical Director    contracts for Catalyst, DBIx::Class and BAST. Contact
Shadowcat Systems Ltd.  mst (at) shadowcatsystems.co.uk for more information

 + Help us build a better perl ORM: http://dbix-class.shadowcatsystems.co.uk/ +