$ git clone -n https://src.fedoraproject.org/rpms/libb2.git /var/lib/mock/f31-build-87034-31726/root/chroot_tmpdir/scmroot/libb2
Cloning into '/var/lib/mock/f31-build-87034-31726/root/chroot_tmpdir/scmroot/libb2'...
$ git reset --hard 669efe70069403251c23201c2b478a63ba80803c
HEAD is now at 669efe7 - Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild