Question

This error is appearing in httpd's error_log ... does APR make any sense here? Looking into Error.pm at line 403 we see throw $err if defined($err);

shouldn't it be looking in package Error? Thanks in advance.

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[Tue Mar 28 13:52:33 2006] [error] Can't locate object method "throw" via package "APR::Error" at /var/www/twiki-4.0.1/lib/CPAN/lib///Error.pm line 403.\n at /var/www/twiki-4.0.1/lib/CPAN/lib///Error.pm line 403\n\tError::subs::try('CODE(0xabd9f7c)', 'HASH(0xaba8ff8)') called at /var/www/twiki-4.0.1/lib/TWiki/UI.pm line 146\n\tTWiki::UI::run('CODE(0x9d0d45c)') called at /var/www/twiki/bin/view line 31\n\tModPerl::ROOT::ModPerl::Registry::var_www_twiki_bin_view::handler('Apache2::RequestRec=SCALAR(0x9c33e3c)') called at /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi/ModPerl/RegistryCooker.pm line 203\n\teval {...} called at /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi/ModPerl/RegistryCooker.pm line 203\n\tModPerl::RegistryCooker::run('ModPerl::Registry=HASH(0xaa6d598)') called at /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi/ModPerl/RegistryCooker.pm line 169\n\tModPerl::RegistryCooker::default_handler('ModPerl::Registry=HASH(0xaa6d598)') called at /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi/ModPerl/Registry.pm line 30\n\tModPerl::Registry::handler('ModPerl::Registry', 'Apache2::RequestRec=SCALAR(0x9c33e3c)') called at -e line 0\n\teval {...} called at -e line 0\n

Environment

-- DickWieland - 28 Mar 2006

Answer

Hmmm. Curious. It looks like the error is in the Error module, and not in TWiki. TWiki has found the Error module OK, but then a call to the function "throw" inside the Error modulle itself is not being resolved, even though Error defines throw. It looks as if mod_perl is getting the namespaces mixed up (I have no idea how).

-- CrawfordCurrie - 30 Mar 2006

It is indeed Error.pm which is sloppy: If $@ contains any object reference, then Error.pm silently, and sometimes wrongly, assumes that it is a reference to an Error object.

The problem can be easily reproduced by a short program:

use Error qw( :try );

try {blubber();};

sub blubber {
    try {die (bless {},'Flubber');};
}

This, however, doesn't explain why mod_perl is throwing an APR::Error in the first place.

-- HaraldJoerg - 30 Mar 2006

Has anyone ever found a solution to this problem?

-- MichaelMazza - 09 Jan 2007

There is a solution:

1. install all required perl modules (see INSTALL.html) especially the 'included' modules (use CPAN or if you use Linux install libperl packages)
2. remove lib/CPAN from the TWiki installation directory
3. restart Apache

-- DanielRohde - 24 Jan 2007

See also HowToInstallCpanModules.

-- PeterThoeny - 24 Jan 2007

The replacement of the 'included' modules produces a new problem: The user gets a ugly error message:

Software error:

Undefined subroutine &TWiki::UI::run called at /twiki/twiki/bin/view line 31.

A page reload works after that.

-- DanielRohde - 01 Feb 2007

Just a guess: Check if absolute path is defined in bin/LocalLib.cfg

-- PeterThoeny - 01 Feb 2007