$ git clone -n https://src.fedoraproject.org/rpms/rust-blake2.git /var/lib/mock/f38-build-side-43-rust-devel-1411405-31435/root/chroot_tmpdir/scmroot/rust-blake2
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1411405-31435/root/chroot_tmpdir/scmroot/rust-blake2'...
$ git fetch origin e3e9b517191f586af1d4981ece546d0715245814:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-blake2
 * [new ref]         e3e9b517191f586af1d4981ece546d0715245814 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e3e9b51 Regenerate with rust2rpm v24