I just updated my rt installation from 4.0.1 to 4.0.2 and everything
went smoothly except for jsmin.
After the upgrade everything worked fine with the normal minifier (the
enabled it in RT_SiteConfig.pm and I got some weird behaviour: the first
time the page loads (after restarting httpd), it is broken and I get a
lot of error messages in the log about RT being unable to connect to the
DB to execute queries (DBD::Pg::st execute failed: could not receive data from
server: Bad file descriptor…). Just reloading the page fixes the
problem and then everything seems to work ok.
With jsmin disabled everything seems to work fine from the beginning.