$ git clone -n https://src.fedoraproject.org/rpms/rust-gmp-mpfr-sys.git /var/lib/mock/f40-build-2036836-48062/root/chroot_tmpdir/scmroot/rust-gmp-mpfr-sys
Cloning into '/var/lib/mock/f40-build-2036836-48062/root/chroot_tmpdir/scmroot/rust-gmp-mpfr-sys'...
$ git fetch origin 871540f85a54a3388ae655147d01bd1702633261:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gmp-mpfr-sys
 * [new ref]         871540f85a54a3388ae655147d01bd1702633261 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 871540f Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild