gnu-tar 1.28

This is the temporary upstream patch suggested. It didn’t seem to do
the trick on my end, but I’m going to get the bot to test it anyway to
rule out any 10.10 errors. This is an ongoing discussion, and may well
require a significant patch if this one doesn’t work. Apparently,
according to upstream, we should be seeing these xattrs errors with the
1.27.1 version as well, but clearly we aren’t, so that’s a little odd.