Item1026: TWikiCompatibilityPlugin fails with DBCachePlugin

On a fresh foswiki-1.0.0 installation extension "DBCachePlugin" fails:

[Mon Feb 02 01:41:44 2009] [notice] Apache/2.2.11 (Unix) mod_perl/2.0.4 Perl/v5.10.0 configured -- resuming normal operations
Can't locate TWiki/Contrib/DBCacheContrib.pm in @INC (@INC contains: /WEB_DATA/foswiki/foswiki-prd/lib/CPAN/lib /WEB_DATA/foswiki/foswiki-prd/lib /swmtools/lib/perl5/5.10.0/sun4-solaris-thread-multi /swmtools/lib/perl5/5.10.0 /swmtools/lib/perl5/site_perl/5.10.0/sun4-solaris-thread-multi /swmtools/lib/perl5/site_perl/5.10.0 /WEB_DATA/foswiki /WEB_DATA/foswiki/lib/perl) at /WEB_DATA/foswiki/foswiki-prd/lib/TWiki/Plugins/DBCachePlugin/Core.pm line 41.

Before the move of the DBCacheContrib to foswiki namespace the DBCachePlugin worked fine.

-- StefanPalm

Stefan,

I'm presuming that you had installed and were running DBCachePlugin before the conversion? And that since then you've not run configure (or perhaps you have and found a bug in that..)

basically, Configure stores the Perl module name (in your case TWiki::Contrib::DBCacheContrib) in the LocalSite.cfg, and this (I suspect) needs to be updated. re-running configure and saving should update this correctly, if not, I think this is a bug in configure, not in TWikiCompatibilityPlugin. (i'm crossing fingers that my guesses are right)

can you please take a look into your lib/LocalSite.cfg and then see what happens when you go through configure save again?

-- SvenDowideit - 08 Feb 2009

Actually I found the problem on a new installation which I created two weeks after the other. In the old/first installation everything works like expected, in the new installation I get the described problem (BTW both installations share the same perl). Just for curiosity I updated the old installation with the new DBCacheContrib; after running "/bin/configure" no changes where made in LocalSite.cfg and the same error occurs...

-- StefanPalm - 09 Feb 2009

Got the same problem with a fresh foswiki installation. Thus I had to use TWiki 4.2.4 with the old plugin to solve the problem for a client. What a shame.

-- WolfMarbach - 09 Feb 2009

As far as I can see, this bug has nothing to do with TWikiCompatibilityPlugin itself.

The recent rebranding of DBCacheContrib by Crawford also came with a significant rewrite that is incompatible with the current DBCachePlugin. I had no time to port DBCachePlugin to the new technology that the recent DBCacheContrib offers. So far, I can provide a new DBCacheBundle consisting of a DBCachePlugin plus a still compatible DBCacheContrib.

-- MichaelDaum - 09 Feb 2009

I've uploaded a new DBCachePlugin that comes bundled with a compatible version of the DBCacheContrib now.

-- MichaelDaum - 09 Feb 2009

Thanks Michael. Now it works. It is a good example of poor coordination. If there are changes in a contrib/plugin there should be a cross reference check to ensure dependent plugins won't fail. I recommend to improve the project management of Foswiki. Otherwise these things annoy people even if a product might be better (which I do not see proven yet).

-- WolfMarbach - 10 Feb 2009

I'd like to point out that a community-driven open source project has some characteristics that make it very difficult to apply classic project management techniques. One of these characteristics is that people work on what they like/can, in the time they have available. This introduces a new paradigm and I don't see the situation on this task as a PM failure, but as an open-source beauty: Michael develops a plugin that depends on a contrib developed by Crawford. Crawford had the time to convert his contrib to Foswiki namespace. Michael didn't have the time to update his plugin yet. This situation caused problems and Stefan reported this. And here we are: from the report to the solution in less than 24 hours! And it just happened, without the need to have someone dictating how and when to do things.

Thank you very much Stefan for reporting this issue and to all those who helped by giving constructive comments and providing a solution!

-- GilmarSantosJr - 10 Feb 2009

Re-opened because I just ported DBCachePlugin to the Foswiki namespace; took about 15 minutes. Not sure it works properly yet; I only did cursory testing, because there are no testcases in the plugin that I could find. Michael, do you have any tests?

-- CrawfordCurrie - 18 Jun 2009

Thanks a lot Crawford. This is excellent news. I will test it out as soon as I can and reopen another bug item as far as needed to report any errors. This one can be closed afaics.

-- MichaelDaum - 19 Jun 2009