$ git clone -n https://src.fedoraproject.org/rpms/rust-capnp-rpc.git /var/lib/mock/f39-build-1526167-36059/root/chroot_tmpdir/scmroot/rust-capnp-rpc
Cloning into '/var/lib/mock/f39-build-1526167-36059/root/chroot_tmpdir/scmroot/rust-capnp-rpc'...
$ git fetch origin 065fadd173b107a849c3caa991b988a4b16cc5b8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-capnp-rpc
 * [new ref]         065fadd173b107a849c3caa991b988a4b16cc5b8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 065fadd Regenerate with rust2rpm v24