$ git clone -n https://src.fedoraproject.org/rpms/R-IRdisplay.git /var/lib/mock/f45-build-5884-345/root/chroot_tmpdir/scmroot/R-IRdisplay
Cloning into '/var/lib/mock/f45-build-5884-345/root/chroot_tmpdir/scmroot/R-IRdisplay'...
$ git fetch origin c4d9740ab81e53aeca1636a84141a7d3a3a8a074:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-IRdisplay
 * [new ref]         c4d9740ab81e53aeca1636a84141a7d3a3a8a074 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c4d9740 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild