Tatsuo Ishii <ishii@postgresql.org> writes:
> I ran autoconf 2.69 on my Ubuntu 20.04 laptop and got the same diffs
> plus diffs related runstatedir:
> + --runstatedir=DIR modifiable per-process data [LOCALSTATEDIR/run]
> If my understanding is correct, configure in the git repository has
> been generated by autoconf 2.69 too. Maybe autoconf 2.69 generates
> slightly different results depending on platform?
If you use a vendor-supplied package of autoconf, you are likely
to get such diffs because of vendor patches. The expectation in
our usage is that committers will use exactly the GNU release
of autoconf, which is available from
https://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.gz
IME it's pretty painless to build it from source, so this isn't
a big deal. I recommend installing it into its own directory
(so it doesn't get messed up by system-software updates) and
adding that directory to your PATH.
regards, tom lane