$ git clone -n https://src.fedoraproject.org/rpms/R-png.git /var/lib/mock/f29-build-1157-480/root/thebuilddir/tmp/scmroot/R-png
Cloning into '/var/lib/mock/f29-build-1157-480/root/thebuilddir/tmp/scmroot/R-png'...
$ git reset --hard a0b9be8d03e298b2d9541bbbd4e5eadaaceac6f8
HEAD is now at a0b9be8 - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild