The current documentation on debugging a grammar (node
"Debugging" in lang-support-guide.texi) does not
mention several useful functions like
semantic-analyze-current-context which can be quite
useful when debugging.
Hints to legitimate procedures for working through a
grammar in a bottom-up fashion (e.g., changing %start
if it worked properly) and providing a simple
interactive function for taking a string to a parse
tree would be useful as well.
I've written a grammar for PVS
(http://pvs.csl.sri.com/) and getting it to work has
been a beast because of the existing limited debugging