I close the issue. I tested manually: the fix works as expected.

I reproduced https://bugzilla.redhat.com/show_bug.cgi?id=1871992#c1 bug (I had to comment the workaround of the mercurial package in Fedora) on 3.9:

make[1]: Entering directory '/home/vstinner/mercurial/mercurial-5.4/doc'
/home/vstinner/python/3.9/python gendoc.py "hgrc.5" > hgrc.5.txt.tmp
python: Python/Python-ast.c:231: get_ast_state: Assertion `state != NULL' failed.

I confirm that the fix in 3.9 works as expected:

> New changeset 55e0836849c14fb474e1ba7f37851e07660eea3c by Pablo Galindo in branch '3.9'

=> No crash with this fix.


I also reproduced the bug in the master branch (without the fix), and I also confirm that the fix in master does fix the crash.