In the Lilypond code we use (debug-enable 'debug) to give full error information when we have Scheme lines embedded in a LilyPond source file.
This option has been deprecated in V2.0 but there's no indication in NEWS of how to supply equivalent functionality. We'd like to know how to crack this so we don't have to run with deprecated Guile code when running with V2. Cheers, Ian Hulin