$ git clone -n https://src.fedoraproject.org/rpms/perl-Spiffy.git /var/lib/mock/f45-build-26232-616/root/chroot_tmpdir/scmroot/perl-Spiffy
Cloning into '/var/lib/mock/f45-build-26232-616/root/chroot_tmpdir/scmroot/perl-Spiffy'...
$ git fetch origin 56128520d841a04f89dc51c6b8f91a83927402cb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Spiffy
 * [new ref]         56128520d841a04f89dc51c6b8f91a83927402cb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5612852 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild