$ git clone -n https://src.fedoraproject.org/rpms/perl-V.git /var/lib/mock/f45-build-27352-622/root/chroot_tmpdir/scmroot/perl-V
Cloning into '/var/lib/mock/f45-build-27352-622/root/chroot_tmpdir/scmroot/perl-V'...
$ git fetch origin 78803eb0862a0d2f5ed031be639658cced6b239a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-V
 * [new ref]         78803eb0862a0d2f5ed031be639658cced6b239a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 78803eb Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild