$ git clone -n https://src.fedoraproject.org/rpms/rust-loopdev.git /var/lib/mock/f39-build-1535215-36246/root/chroot_tmpdir/scmroot/rust-loopdev
Cloning into '/var/lib/mock/f39-build-1535215-36246/root/chroot_tmpdir/scmroot/rust-loopdev'...
$ git fetch origin 692ef65caffd99cbf34d91bad443acd856ec43be:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-loopdev
 * [new ref]         692ef65caffd99cbf34d91bad443acd856ec43be -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 692ef65 Regenerate with rust2rpm v24