No manual entry error

Problem

After installing some applications, I found that man no longer worked on my computer:

$ man gcc
No manual entry for gcc
See 'man 7 undocumented' for help when manual pages are not available.

Solution

Turns out that one of the applications needed to add its manpage. It did this by adding its path to MANPATH like this in Fish’s config.fish:

set --export MANPATH $MANPATH /path/to/app

Changing it to the below fixed the error:

set --export MANPATH ":/path/to/app"