Comment 4 for bug 877466

Sorry, the notes are as clear as they can be, but they can't intend to be a course about Unix system administration.

Sopy, copy/paste mode:

Users who want to share databases in the main directory (/var/lib/geneweb)
have to be members of the geneweb group (just like the geneweb user is).
All files and directories there should be writable by the owning user AND
the geneweb group. This means that you should use 002 as umask when writing
to this directory. Users with the more common 022 umask must then
temporarily change it before creating files, or need to adapt
directories and files permissions in /var/lib/geneweb after adding
a database.

This inludes files in the base.gwb directory as well as files created
by the daemon during its work (such as "history" of .lck files...)
should be writable by both the database owner (for allowing him for
manually make modifications from the shell) and the geneweb group.