[Trisquel-users] Missing manpages

[s1lv3r1997]

I noticed that some man pages are missing in trisquel for make an example   
hier(7) and umask(2), i tried to use mandb but nothing happens.
Why this pages are missing?
I posted this on the italian forum but nobody  seems to know exactly why this  
pages are missing, i know this is not a big deal since you can read man pages  
online, but this intrigued me.
Sorry if my english is not perfect i'm trying to improve it