$ git clone -n https://src.fedoraproject.org/rpms/perl-Throwable.git /var/lib/mock/f45-build-27142-621/root/chroot_tmpdir/scmroot/perl-Throwable
Cloning into '/var/lib/mock/f45-build-27142-621/root/chroot_tmpdir/scmroot/perl-Throwable'...
$ git fetch origin d8582d2e3475e5a6cce6a0d1e3da588ea27ccc40:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Throwable
 * [new ref]         d8582d2e3475e5a6cce6a0d1e3da588ea27ccc40 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d8582d2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild