$ git clone -n https://src.fedoraproject.org/rpms/stxxl.git /var/lib/mock/f31-build-74019-31067/root/chroot_tmpdir/scmroot/stxxl
Cloning into '/var/lib/mock/f31-build-74019-31067/root/chroot_tmpdir/scmroot/stxxl'...
$ git reset --hard d7bc6bfaae8abf77d6088459c5186f410c93346f
HEAD is now at d7bc6bf - Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild