A couple of days ago I was fixing the fortinet/fortigate with the kind help of a Swiss OSSIM user (thanks Mikael ;-) ) and I wrote this little piece of python in order to help me out with it. Now I'm using it a lot to debug plugins so I guess more people could benefit from this also :-)
And well, I'll paste a sample plugin debugging session in order to give ideas.
BTW, this assumes basic knowledge of regular expressions, check this Regexp Primer out if you want to refresh that knowledge. And BTW2, some log lines are broken for readability.