$ git clone -n https://src.fedoraproject.org/rpms/xcb-util-errors.git /var/lib/mock/f45-build-38639-726/root/chroot_tmpdir/scmroot/xcb-util-errors
Cloning into '/var/lib/mock/f45-build-38639-726/root/chroot_tmpdir/scmroot/xcb-util-errors'...
$ git fetch origin 0fd4b58b5c0b317c70e1028440d34c756c83e1c1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xcb-util-errors
 * [new ref]         0fd4b58b5c0b317c70e1028440d34c756c83e1c1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0fd4b58 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild