app_fax no longer seems to be part of asterisk-addons, so the USE flag should be removed to prevent confusion. Reproducible: Always Steps to Reproduce: 1. upgrade to asterisk-addons-1.6.0.1 2. scratch your head wondering where app_fax has gone to.
It has been confirmed by the ChangeLog: r615 | russell | 2008-06-02 11:15:45 -0500 (Mon, 02 Jun 2008) | 2 lines Remove app_fax, as it has been moved into the main Asterisk repository ........ Fixed.