The doc USE flag description indicates that it is for API and other developer related documentation. The muttrc manpage is actually user documentation that is needed to understand configuration of the application. However, unless the USE=doc is set, the muttrc manpage isn't installed. Please add this manpage to the normal installed documentation. Reproducible: Always Steps to Reproduce: 1. Emerge mutt with USE=-doc 2. muttrc manpage unavailable 3. Change USE flag to +doc, and muttrc(5) is now available.
fixed in mutt-1.5.21-r4, thanks