I'll see if I can find the guilty grammar on my old HDD; it was one of my first tries with LPeg (thus probably rather... suboptimal), it parsed plain text and
stored a fair number of values (like 50 or more) in nested tables.
I cant even remember the assertions output, but IIRC it was something along the lines of "maximum stack size exceeded". After compiling LPeg with NDEBUG,
everything worked like a charm.
If I can recover the grammar (or reproduce the error), I'll post further information.
PS: LPeg version was 0.9 and the grammar was one huge table- hope that helps.