$ git clone -n https://src.fedoraproject.org/rpms/libunwind.git /var/lib/mock/f40-build-789649-135946/root/chroot_tmpdir/scmroot/libunwind
Cloning into '/var/lib/mock/f40-build-789649-135946/root/chroot_tmpdir/scmroot/libunwind'...
$ git fetch origin dd1576a172c37203ed5890edbaf9d4d4c417a6f6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libunwind
 * [new ref]         dd1576a172c37203ed5890edbaf9d4d4c417a6f6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dd1576a Bump and rebuild package (for riscv64)