rails: apache not proxying requests to mongrel cluster
The Apache2 RewriteCond context is supported in the server config, virtual host, directory and .htaccess. The rewrite rules which are meant to proxy requests to the mongrel_cluster were defined outside of the above mentioned context's, which resulted in them not taking effect.
This issue did not arise during testing, as the test case rails application (tracks-1.6) had a fall back rewrite rule for .cgi in its .htaccess, so the application was being served directly from apache.
While testing Rails 2009.03 pre-release with our new test case rails application (tracks-1.7), the bug showed itself due to the fall back rewrite rule being changed to .fcgi (which apache isn't configured to support).