It is just crazy how long lines Shibboleth produces. I made a way to watch these logs easier (for me).
I remove the long class names (it is crazy, I mean it) and add line breaks.

This is it:

tail -f /usr/local/shibboleth-idp-2.2.0-slo9/logs/idp-process.log \
| sed 's,edu.internet2.middleware.shibboleth,SHIB,g' \
| sed 's,\] - ,\]\n  ,'

I had a version that contained one liner perl, but I converted it to sed.