The logback.xml to logback.groovy translator is currently generating code like this:

logger("foo.Bar", INFO)

This causes invalid code in case of inner classes, e.g.

logger("foo.Bar$Foobar", INFO)

because the $ is used for variable replacement in Groovy.

I'd suggest to always use

(single quote) for strings, e.g.

logger('foo.Bar$Foobar', INFO)