Question

I'm trying to activate mod_perl (SuSE's apache2-mod_perl-1.99_12_20040302-33 rpm) for my TWiki installation, following the instructions in ModPerlUnix as much as possible. I've put

<FilesMatch "(view).*">
    SetHandler perl-script
    PerlResponseHandler ModPerl::Registry
    PerlOptions +ParseHeaders
    Options +ExecCGI
</FilesMatch>

in .../twiki/bin/.htaccess (the ... are substituted everywhere with the real path, of course), and added PerlSwitches -T to httpd.conf.

I've also tried adding PerlRequire .../twiki/tools/mod_perl_startup.pl to httpd.conf, with .../twiki/tools/mod_perl_startup.pl being

chdir(".../twiki/bin");
eval "require 'setlib.cfg'";

but then Apache won't start, and gives the following error:

[Sat Feb 25 18:25:53 2006] [error] .../twiki/tools/mod_perl_startup.pl did not return a true value at (eval 4) line 1.\n
[Sat Feb 25 18:25:53 2006] [error] Can't load Perl file: .../twiki/tools/mod_perl_startup.pl for server www.example.com:0, exiting...

When viewing some of the topics, I get an error (see below). It doesn't neccessarily happen the first time I view the topic, and sometimes the topic will display fine again a couple of minutes later (but usually the error reoccurs every time). Also some topics that previously displayed fine, will now start giving the error.

Topics that are prone to trigger the error are Main.WebChanges, TWiki.WebChanges, Sandbox.WebHome and Sandbox.WebStatistics

The error messages when viewing Main.WebChanges are: In the browser:

TWiki detected an internal error - please check your TWiki logs and webserver logs for more information.

RCS: path  -h %FILENAME|F% of path-project.orgpath,v failed: 
RCS file: path-project.orgpath,v
Working file: PatternSkinUserViewTemplate.txt
head: 1.1
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 1
=============================================================================

In apache's error_log:

********************************
RCS: /usr/bin/rlog  -h %FILENAME|F% of .../twiki/data/Main/PatternSkinUserViewTemplate.txt,v failed: 
RCS file: .../twiki/data/Main/PatternSkinUserViewTemplate.txt,v
Working file: PatternSkinUserViewTemplate.txt
head: 1.1
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 1
=============================================================================

For other topics, the named "Working file" can be WebTopicCreator.txt, PatternSkinJavascripts.txt or TWikiReleaseNotes04x00x00.txt (others have occurred, as well).

Sometimes, after this error has started occuring, a different error message occurs:

TWiki detected an internal error - please check your TWiki logs and webserver logs for more information.

Can't locate TWikipath in @INC (@INC contains: path-lib path-linux-thread-multi path path-linux-thread-multi path path path-linux-thread-multi path path path path)

Can't locate TWiki/Plugins/SpreadSheetPlugin/Calc.pm in @INC (@INC contains: /srv/www/perl-lib /usr/lib/perl5/5.8.3/i586-linux-thread-multi /usr/lib/perl5/5.8.3 /usr/lib/perl5/site_perl/5.8.3/i586-linux-thread-multi /usr/lib/perl5/site_perl/5.8.3 /usr/lib/perl5/site_perl /usr/lib/perl5/vendor_perl/5.8.3/i586-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.3 /usr/lib/perl5/vendor_perl /srv/www/  /srv/www/lib/perl) at .../twiki/lib/TWiki/Plugins/SpreadSheetPlugin.pm line 83.

I've also tried to activate mod_perl on other scripts beside view, but then I frequently get errors like

Can't locate TWiki/UI/Edit.pm in @INC (@INC contains: . /srv/www/perl-lib /usr/lib/perl5/5.8.3/i586-linux-thread-multi /usr/lib/perl5/5.8.3 /usr/lib/perl5/site_perl/5.8.3/i586-linux-thread-multi /usr/lib/perl5/site_perl/5.8.3 /usr/lib/perl5/site_perl /usr/lib/perl5/vendor_perl/5.8.3/i586-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.3 /usr/lib/perl5/vendor_perl . /srv/www/ /srv/www/lib/perl) at .../twiki/bin/edit line 32. BEGIN failed--compilation aborted at .../twiki/bin/edit line 32. 

Any help would be appreciated!

Environment

-- BjornHelgeMevik - 25 Feb 2006

Answer

If you answer a question - or someone answered one of your questions - please remember to edit the page and set the status to answered. The status selector is below the edit box.

As for the did not return a true value and Can't locate TWikipath in @INC: This looks like a bogus path to setlib.cfg, or a bogus content in setlib.cfg.

If you are using a mod_perl startup file, I think it is best to just set the library paths and include the modules there:

use lib "your/path/to/twiki/lib";
use CGI;
CGI->compile();
use TWiki;
use TWiki::UI;
# repeat ad nauseam for whatever modules you see fit

The problem with the lock files - hmmm. Have you been upgrading from Dakar? Or have you changed the userid of your webserver? It might be necessary to break the locks, or to chown the files. Difficult to tell, from here.

-- HaraldJoerg - 25 Feb 2006

The did not return a true value did turn out to happen because the mod_perl_startup.pl did not end with 1;. Adding this (an a line of its own), made Apache happy.

However, it did not solve the other problems.

What did alleviate them, though, was to remove the PerlSwitches -T from httpd.conf. The errors still occur from time to time, but much more seldom, and I've been able to activate mod_perl for more scripts (I haven't tested thoroughly yet, but so far only attach and save seem to (consistently) give strange results.)

(I played around with the -T, and found out that with -T, @INC does not contain ".", so the require in mod_perl_startup.pl will not find setlib.cfg (but the error is suppressed because of the eval). Probably something like unshift @INC, '.'; should be included prior to the require (this is what's done in view, etc.).)

As for the RCS problems, the TWiki installation is not an upgraded Cairo, it is a freshly installed 4.0.1, and I have not changed the uid/gid of Apache. (Also, as mentioned, the error doesn't occur every time i visit the topic.)

Now, removing the taint checking is bad for security, and the problems are not completely gone, so any help or ideas are greatly appreciated!

-- BjornHelgeMevik - 26 Feb 2006

Is there a reason you can't just use PerlSwitches -T -I . ?

-- CrawfordCurrie - 27 Feb 2006

Nothing except my ignorance. -- BjornHelgeMevik - 01 Mar 2006

i think you can get by by doing something along the lines of: require './setlib.cfg'; (just put ./ in the filename).

-- WillNorris - 27 Feb 2006

With your suggestions I now have a mod_perl setup with taint checking and correct @INC. Thanks!

Unfortunately, that didn't solve the RCS problem mentioned above. It still occurs (in a seemingly-random fashion).

-- BjornHelgeMevik - 01 Mar 2006

Now I have researched a little more. The rlog error gets thrown in TWiki::Store::RcsWrap::numRevisions because the $error from sysCommand is 16777215.

From the error log, it seems that rlog returns what it is supposed to. I wrapped rlog in a shell script that logged the exit code ($?) of rlog before exiting with the same exit code, and indeed rlog finishes successfully, i.e., with zero exit code.

I then logged $? and $! after close $handle in TWiki::Sandbox::sysCommand, and it turns out that $? is -1 and $! is 'No child processes' when the problem occurs.

Could this mean that rlog runs withtout error, but finishes before close is called? And is this something that can be caught (by treating $? = -1= specially), or would $? = -1= occur for "real" errors as well?

-- BjornHelgeMevik - 02 Mar 2006

I have the same problem as Bjorn. In our TWiki install at my work the 'Erroneous RLog Internal Error' (ERIE) appearing more and more often on submitting a page. I have to say that this error is the one that might cause me to migrate from TWiki. I'll take a look at it myself, but I haven't much time to spend on it. Any help would be gratefully received.

I'm taking the liberty of changing the Support Status back to 'Asked Questions'...if that's not the correct procedure, then I apologise.

-- AnthonyDervish - 22 May 2006

I stopped investigating the problem after I discovered another show stopper for using mod_perl with TWiki (at least for me): It seems more or less impossible to have several TWikis running under mod_perl on the same physical host. And the host I use does run several TWikis.

It would be nice to see the problem solved, though.

-- BjornHelgeMevik - 22 May 2006

Closing this. Please drop by IRC if you want to investigate this further, "Lavr" and others have gained some mod_perl knowledge and might have suggestions worth exploring.

-- SteffenPoulsen - 16 Jun 2006