There is a cronjob that runs on buildbot-vm.a.o to convert rat-output.xml to rat-output.html that then gets displayed in the following places:
If rat-output.xml contains invalid HTML characters, you need to find which files are causing that and add them to rat-excludes.txt on the build client or, in the case of Tomcat, submit a bug with the info and they will update their rat-excludes.txt file. See bug 61554 for reference.
To find the specific files in rat-output.xml you have to use a script that I wrote and need to put somewhere.
You can also run iconv -f us-ascii -t utf-8 rat-output.xml
to parse the file and show you the first occurrence of an invalid character. You can then take the location number, use vim +whateverNumbergo filename.xml
, then scroll up to find the xml element resource-name, and that will contain the filename.