probably lots of others). The $PATH used to invoke the filter
didn't contain Ghostscript and Perl, so it silently fails. (A nice
property of CUPS is that it will just silently discard the job when
that happens, so you need to set LogLevel to "debug" to see this.)
Fortunately, CUPS now has a "SetEnv" option to set $PATH explicitly.
Also, remove config.system.path from the PATH of CUPS' Upstart job.
It seems to serve no purpose.
svn path=/nixos/trunk/; revision=34244