The compiler has generated intermediate code which uses a 77-tuple, but unfortunately the libraries don't contain code for 77-tuples (we only go up to 62-tuples).

This is kind of a known bug, occasionally tickled by Happy-generated parsers.

If you're not generating your parser with 'happy -agc', then that should help.

Cheers, Simon

Thank you a lot. As simple as it is, it really helped. Thanks to Volker and Johannes, too. Greetings, Frank-Andre