$ git clone -n https://src.fedoraproject.org/rpms/rust-prost0.8.git /var/lib/mock/f40-build-2130693-50793/root/chroot_tmpdir/scmroot/rust-prost0.8
Cloning into '/var/lib/mock/f40-build-2130693-50793/root/chroot_tmpdir/scmroot/rust-prost0.8'...
$ git fetch origin 155cd62a3d58f8b56950c7b14f568ac8d3a702aa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-prost0.8
 * [new ref]         155cd62a3d58f8b56950c7b14f568ac8d3a702aa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 155cd62 Regenerate with rust2rpm v25