$ git clone -n https://src.fedoraproject.org/rpms/exim.git /var/lib/mock/f45-build-8547-390/root/chroot_tmpdir/scmroot/exim
Cloning into '/var/lib/mock/f45-build-8547-390/root/chroot_tmpdir/scmroot/exim'...
$ git fetch origin 7c018cb611584ad56db25e436df99c90f1668cac:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/exim
 * [new ref]         7c018cb611584ad56db25e436df99c90f1668cac -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7c018cb Perl 5.44 re-rebuild updated packages