$ git clone -n https://src.fedoraproject.org/rpms/perl-Test-Is.git /var/lib/mock/f45-build-26688-618/root/chroot_tmpdir/scmroot/perl-Test-Is
Cloning into '/var/lib/mock/f45-build-26688-618/root/chroot_tmpdir/scmroot/perl-Test-Is'...
$ git fetch origin f610284653f22a2be18cb6a551c8c93be22a38c4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Test-Is
 * [new ref]         f610284653f22a2be18cb6a551c8c93be22a38c4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f610284 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild