Add /var/lib/mock to PRUNEPATHS
    
    /var/lib/mock contains copy of OS. It is inteded for building packages. It usually contains duplicates to what you are looking for.

    E.g.

    

    ```

    $ locate bash/FAQ

    /usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-24-x86_64-28570-30325/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-24-x86_64-28683-31985/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-24-x86_64-29477-7840/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-24-x86_64-32229-16460/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-25-x86_64/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-25-x86_64-18827-15085/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-25-x86_64-27938-29561/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-25-x86_64-bootstrap-27938-29561/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-26-i386-999/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-26-i386-bootstrap-999/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-26-x86_64/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-28-x86_64/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-29-x86_64/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-30-x86_64/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-31-x86_64/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-31-x86_64-bootstrap/root/usr/share/doc/bash/FAQ

    /var/lib/mock/fedora-rawhide-x86_64/root/usr/share/doc/bash/FAQ

    /var/lib/mock/rhelbeta-8-x86_64/root/usr/share/doc/bash/FAQ

    ```