$ git clone -n https://src.fedoraproject.org/rpms/rust-gtk.git /var/lib/mock/f40-build-2072773-49334/root/chroot_tmpdir/scmroot/rust-gtk
Cloning into '/var/lib/mock/f40-build-2072773-49334/root/chroot_tmpdir/scmroot/rust-gtk'...
$ git fetch origin 168729806c114527a7f8e994fad81a4e03cae6c2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gtk
 * [new ref]         168729806c114527a7f8e994fad81a4e03cae6c2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1687298 Update to version 0.18.1; Fixes RHBZ#2231718