$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_spanned.git /var/lib/mock/f38-build-side-42-init-devel-621765-26349/root/chroot_tmpdir/scmroot/rust-serde_spanned
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-621765-26349/root/chroot_tmpdir/scmroot/rust-serde_spanned'...
$ git fetch origin 81bcdba8f5678bc589247bff09398e48ff865a88:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_spanned
 * [new ref]         81bcdba8f5678bc589247bff09398e48ff865a88 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 81bcdba Initial import (#2183332)