Unlike GNU diff, Solaris's diff formats dates according to the current locale. For example:
> echo foo > foo > env LANG=C diff -u /dev/null foo --- /dev/null Tue Oct 21 14:34:01 2014 +++ foo Tue Oct 21 14:24:53 2014 @@ -1,0 +1,1 @@ +foo > env LANG=fr_FR diff -u /dev/null foo --- /dev/null mar. oct 21 14:33:51 2014 +++ foo mar. oct 21 14:24:53 2014 @@ -1,0 +1,1 @@ +foo
This isn't matched by the regular expression in ArcanistDiffParser.php, and prevents such diffs from being uploaded with the form at /differential/diff/create/.