$ git clone -n https://src.fedoraproject.org/rpms/cosmic-comp.git /var/lib/mock/f41-build-side-1-3097265-39322/root/chroot_tmpdir/scmroot/cosmic-comp
Cloning into '/var/lib/mock/f41-build-side-1-3097265-39322/root/chroot_tmpdir/scmroot/cosmic-comp'...
$ git fetch origin c2e49445684da1e8cb4510a67e9123f025f9f417:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cosmic-comp
 * [new ref]         c2e49445684da1e8cb4510a67e9123f025f9f417 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c2e4944 "Update to 1.0.0~alpha.3"