Please use the perl debugger: investing some time to learn is pays back really quick. Here's a very tiny howto.
Start the debugger as e.g.
perl -d `which lr_log2report` -o xml combined < tmp/log > /dev/null
After starting the debugger, run "v" and "c lineno" to make sure all modules are loaded. Once that's done, you can fast-forward to a relevant routine using e.g. "c Lire::DlfAnalysers::ReferrerCategoriser::categorise". Now you can inspect variables and evaluate expressions by running e.g.
DB<12> x $parsed_url->{'query'}
Also, be sure to try the commands "s" and "r". Just these 4 command very likely are enough to get your job done. (The "y" command might be useful too, though). See perldebug(1) and perldebtut(1) for more information.