I just installed xcache on my server (Fedora 16) following the tutorial on http://xcache.lighttpd.net/wiki/InstallFromSource.
When I try to run my Symfony2 app I get the following error:
Cannot redeclare class AppKernel
When I disable xcache, then Symfony2 is working perfectly again.
It was because I had APC already installed, and there is apparently a conflict between xcache and apc