$ git clone -n https://src.fedoraproject.org/rpms/gnome-js-common.git /var/lib/mock/f41-build-756800-13422/root/chroot_tmpdir/scmroot/gnome-js-common
Cloning into '/var/lib/mock/f41-build-756800-13422/root/chroot_tmpdir/scmroot/gnome-js-common'...
$ git fetch origin 34d09d31d9b13ed233d66901eb06c200c042e146:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-js-common
 * [new ref]         34d09d31d9b13ed233d66901eb06c200c042e146 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 34d09d3 Eliminate use of obsolete %patchN syntax (#2283636)