"make regen-all" now produces the same output when run from a
directory other than the source tree: when building Python out of the
source tree.
(cherry picked from commit 253b7a0a9f)
(cherry picked from commit b6defde2af)
Currently, empty sequences in gather rules make the conditional for
gather rules fail as empty sequences evaluate as "False". We need to
explicitly check for "None" (the failure condition) to avoid false
negatives.
(cherry picked from commit e55a0e9)
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>