I'm using Pygments 1.3.1 and I wrote a custom formatter. Looks like some lexer(s) are giving me Token.Literal.String.Regexp token type sometimes which make style_for_token fail. I can see that there is a Token.Literal.String.Regex in token.py but no Token.Literal.String.Regexp, maybe it has been renamed at some point and forgotten in some lexers or it's just a error in a lexer. I can find one in lexers/agile.py line 900 for example.
Issue #625 resolved