$ git clone -n https://src.fedoraproject.org/rpms/grpc.git /var/lib/mock/f39-build-2101857-50513/root/chroot_tmpdir/scmroot/grpc
Cloning into '/var/lib/mock/f39-build-2101857-50513/root/chroot_tmpdir/scmroot/grpc'...
$ git fetch origin 4551c62449f7551aa9b00784925af8d1ad6081b5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/grpc
 * [new ref]         4551c62449f7551aa9b00784925af8d1ad6081b5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4551c62 Rebuild for abseil-cpp-20230802.0