$ git clone -n https://src.fedoraproject.org/rpms/gnome-builder.git /var/lib/mock/f41-build-side-1-3002567-36559/root/chroot_tmpdir/scmroot/gnome-builder
Cloning into '/var/lib/mock/f41-build-side-1-3002567-36559/root/chroot_tmpdir/scmroot/gnome-builder'...
$ git fetch origin c6a959add98eaeb8a41fb036c2f756f066fa1967:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-builder
 * [new ref]         c6a959add98eaeb8a41fb036c2f756f066fa1967 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c6a959a Update to 47.2