$ git clone -n https://src.fedoraproject.org/rpms/perl-File-Slurp.git /var/lib/mock/f45-build-23589-598/root/chroot_tmpdir/scmroot/perl-File-Slurp
Cloning into '/var/lib/mock/f45-build-23589-598/root/chroot_tmpdir/scmroot/perl-File-Slurp'...
$ git fetch origin 75f731ad7a1ef969e2c108737ad91678f9c937fe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-File-Slurp
 * [new ref]         75f731ad7a1ef969e2c108737ad91678f9c937fe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 75f731a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild