Probably best to leave it, as is, and mark it as known-to-be-unused at least via comment.
How does the text below look for an explanation? (By the way, I noticed that FileUtils.pm, unlike the other *.pm in lib/Automake, doesn't have an =over 4 ... =back around all the other items, causing pod2text to complain. I'll fix that too unless there is some magical reason for it.) --- a/lib/Automake/FileUtils.pm +++ b/lib/Automake/FileUtils.pm @@ -181,7 +181,20 @@ sub update_file ($$;$) =item C<up_to_date_p ($file, @dep)> -Is C<$file> more recent than C<@dep>? +Is C<$file> strictly more recent than C<@dep>? +If mtimes are equal, returns true. + +This function is not used anywhere in Automake. Where it is used is in +C<autom4te>, which is part of Autoconf. And its use there poses a +problem with respect to subsecond timestamps, as discussed at +L<https://lists.gnu.org/archive/html/automake-patches/2020-04/msg00000.html> +(thread continues into May). The best approach seems to be to leave this +function alone, and have C<autom4te> use a different test, one which is +not part of Automake. + +Although we would like to remove this function from Automake, since it's +not used, that would break older versions of Autoconf, which seems +gratuitious. So we leave it, unchanged. =cut compile finished at Sat May 9 18:09:15 2020