Not much important but probably missing:

top_exit--;

in void extract_exit

and also in void pullorpush there is a

top_exit++;

... that there shouldn't be, because make_exit do top_exit++

while it is just used for information, its good to have it fixed. Thanks for finding it.

Thanks, it's been added to the GitHub branch: https://github.com/Arthmoor/SmaugFUSS/commit/c0802f2e3d37c75a52860dab33a8ababf6b7f987