$ git clone -n https://src.fedoraproject.org/rpms/perl-XML-Tiny.git /var/lib/mock/f45-build-27661-625/root/chroot_tmpdir/scmroot/perl-XML-Tiny
Cloning into '/var/lib/mock/f45-build-27661-625/root/chroot_tmpdir/scmroot/perl-XML-Tiny'...
$ git fetch origin 3f86a6708518fbe463be019675c9b3c28765e3c9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-XML-Tiny
 * [new ref]         3f86a6708518fbe463be019675c9b3c28765e3c9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3f86a67 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild