On Sun, 4 Apr 2021 at 01:15, Eli Zaretskii <
eliz@gnu.org> wrote:
"make extraclean" is only needed when doing something very drastic,
like switching to a very different branch. That is an extremely rare
(if not improbable) use case, so IMO having everyone pay for it is
unjustified.
I'm not sure that assumption is correct. You can run into this issue just changing commits, not switching branches if that commit is old enough. For example, checking out the emacs-27 tag. I'm also not convinced moving between the last released version and the current development version and back again is that unusual and the longer things go between the last release and current development head, the larger the difference in commits and greater the potential for this sort of issue.
--