$ git clone -n https://src.fedoraproject.org/rpms/perl-Email-Simple.git /var/lib/mock/f45-build-23292-596/root/chroot_tmpdir/scmroot/perl-Email-Simple
Cloning into '/var/lib/mock/f45-build-23292-596/root/chroot_tmpdir/scmroot/perl-Email-Simple'...
$ git fetch origin b73cfc4012ffdedc5ea61523bc673b9ade16a06a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Email-Simple
 * [new ref]         b73cfc4012ffdedc5ea61523bc673b9ade16a06a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b73cfc4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild