Error when trying to start a Catalyst server - perl

Question

Running the Catalyst internal server, located at scripts/MyApp_server.pm, I receive the following error. Is there any one who can help me in this regard?
I have not changed any of the files created by catalyst.pl. I just have run the catalyst.pl MyApp and then run scripts/MyApp_server.pl -r for testing whether Catalyst works or not. This is the only things I have done!
I have reinstalled Catalyst and its dependent modules several times by using either yum and cpan. But it doesn't work again.
Thanks!
THE ERROR MESSAGE:
Can't use an undefined value as a HASH reference at /usr/local/share/perl5/Catalyst.pm line 2681.
BEGIN failed--compilation aborted at /home/Ali/Lab/WEB/catalyst/MyApp3/script/../lib/MyApp3.pm line 20.
Compilation failed in require at /usr/local/lib/perl5/Class/MOP/Method/Wrapped.pm line 50
The codes around line 2681 in /usr/local/share/perl5/Catalyst.pm are as below:
sub setup_home {
my ( $class, $home ) = #_;
if ( my $env = Catalyst::Utils::env_value( $class, 'HOME' ) ) {
$home = $env;
}
$home ||= Catalyst::Utils::home($class);
if ($home) {
#I remember recently being scolded for assigning config values like this
$class->config->{home} ||= $home; # THIS IS LINE 2681
$class->config->{root} ||= Path::Class::Dir->new($home)->subdir('root');
}
}
The content of the lib/MyApp.pm is as below:
package MyApp;
use Moose;
use namespace::autoclean;
use Catalyst::Runtime 5.80;
# Set flags and add plugins for the application
#
# -Debug: activates the debug mode for very useful log messages
# ConfigLoader: will load the configuration from a Config::General file in the
# application's home directory
# Static::Simple: will serve static files from the application's root
# directory
use Catalyst qw/
-Debug
ConfigLoader
Static::Simple
/;
extends 'Catalyst';
our $VERSION = '0.01';
$VERSION = eval $VERSION;
# Configure the application.
#
# Note that settings in myapp.conf (or other external
# configuration file that you set up manually) take precedence
# over this when using ConfigLoader. Thus configuration
# details given here can function as a default configuration,
# with an external configuration file acting as an override for
# local deployment.
__PACKAGE__->config(
name => 'MyApp',
# Disable deprecated behavior needed by old applications
disable_component_resolution_regex_fallback => 1,
);
# Start the application
__PACKAGE__->setup();
=head1 NAME
MyApp - Catalyst based application
=head1 SYNOPSIS
script/myapp_server.pl
=head1 DESCRIPTION
[enter your description here]
=head1 SEE ALSO
L<MyApp::Controller::Root>, L<Catalyst>
=head1 AUTHOR
Ali Basirat
=head1 LICENSE
This library is free software. You can redistribute it and/or modify
it under the same terms as Perl itself.
=cut
1;

Answer 1

This isn't a definitive answer, but hopefully will help a little.
You've either got an undefined $class or $class->config (more likely), although how I can't say. Perhaps the ConfigLoader hasn't worked.
Re-installing things blindly seldom helps and the problem could be due to any module in the dependency list. If there was a specific problem installing a module then there would have been an error and we could have worked on that.
So - using yum install cpanm and local::lib - I'm not sure what the packages are called on Red Hat, but it should be easy enough to find out.
OK - now create a new directory somewhere suitable.
mkdir /home/Devt/catalyst_test
cd /home/Devt/catalyst_test
eval $(perl -Mlocal::lib=./perllib)
echo $PERL5LIB
# You should see your current directory mentioned in PERL5LIB
cpanm Catalyst
cpanm Catalyst::Helper
catalyst.pl MyApp
cd MyApp/
perl Makefile.PL
./script/myapp_server.pl
# Opens up a server on port 3000
What local::lib is doing is setting up the paths to install everything locally (in perllib) - you can see the environment variables it sets up by running it without the eval.
perl -Mlocal::lib=./perllib
See the docs for how to add it to a bash login script. I just redirect the output to a file and source it when I'm working on a project (I use one perllib per project).
Then, cpanm is smart enough to use this local directory to install all the bits you need.
If this doesn't work, the problem is probably due to something you've manually installed in /usr/local/. Take a backup of the various perl-related lib dirs in /usr/local/ and then clean them out. Run cpanm again (checking local::lib paths are setup first) and see if the versions it downloads work.
The above should work - it's exactly what I did 10 minutes ago.
The whole idea of this is to create a separate installation of all your perl libraries for this project - that way if you upgrade anything it only affects the current installation.