If your ebuild requires a user or group to be added for a daemon, for example,
this should be performed via the functions available in user.eclass.
Regardless of whether you are adding a group or a user, this should be performed
in the pkg_setup phase function. pkg_setup is called
before the compile process, with
sandbox
disabled, so a build that requires the user to exist will
have it, and is also called for both binary and source packages. You may also
use the pkg_preinst or pkg_postinst functions for user creation, if
the user is not required during or before src_install.
To add a group, use the enewgroup function:
enewgroup <name> [gid]
By default the next available group ID is selected. To set a specfic group ID,
pass it an extra argument to enewgroup.
To add a user, use the enewuser function:
enewuser <user> [uid] [shell] [homedir] [groups]
By default, both enewuser and enewgroup allocate the next available user
ID or group ID to the new user or group - if not, you explicitly have to specify
one.
Arguments for enewuser must be passed in the order as shown above: if you do
not want to specify a fixed user ID however but do want to set a specific shell,
for example, use -1 for the uid parameter. The same applies for any other
parameter where you want to keep the default setting.
Groups for the groups argument should be separated by a comma (,) and
wrapped correctly, for example:
enewuser frozd -1 -1 -1 "backup,frozd"