$ git clone -n https://src.fedoraproject.org/rpms/erlang-jiffy.git /var/lib/mock/f41-build-811295-147311/root/chroot_tmpdir/scmroot/erlang-jiffy
Cloning into '/var/lib/mock/f41-build-811295-147311/root/chroot_tmpdir/scmroot/erlang-jiffy'...
$ git fetch origin aab260bfb5f26dc9df821b6153ef1ecf507c9518:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-jiffy
 * [new ref]         aab260bfb5f26dc9df821b6153ef1ecf507c9518 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aab260b Rebuild with a fixed Erlang macros