$ git clone -n https://src.fedoraproject.org/rpms/icestorm.git /var/lib/mock/f45-build-13998-456/root/chroot_tmpdir/scmroot/icestorm
Cloning into '/var/lib/mock/f45-build-13998-456/root/chroot_tmpdir/scmroot/icestorm'...
$ git fetch origin af0f9037686050ccdc2b71fdbae16430d551e921:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/icestorm
 * [new ref]         af0f9037686050ccdc2b71fdbae16430d551e921 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at af0f903 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild