$ git clone -n https://src.fedoraproject.org/rpms/perl-Test-Requires-Git.git /var/lib/mock/f45-build-26819-619/root/chroot_tmpdir/scmroot/perl-Test-Requires-Git
Cloning into '/var/lib/mock/f45-build-26819-619/root/chroot_tmpdir/scmroot/perl-Test-Requires-Git'...
$ git fetch origin 75444c148efa799a7356b56fb60b12ced9d1ada2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Test-Requires-Git
 * [new ref]         75444c148efa799a7356b56fb60b12ced9d1ada2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 75444c1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild