On 05/12/2020 10:13, Dale wrote:
> that as, I learned the hard way.  Once you get Gentoo installed and all
> the packages you want installed completed, it is wise to add the
> --oneshot option to the defaults in make.conf.  That helps keep the
> world file clean since you won't have packages in the world file that
> shouldn't be there.  If later you want to add a package to the world
> file, you have to specify that you want it added.  If it is already
> installed, you can do a emerge -n --select y <package name> and it adds
> it to the world file.  It will then be maintained automatically.

Excellent pro-tip for keeping your world file clean! While I personally 
use the reverse of this (i.e. I manually add -1 to things I do not want 
to end up in my world file) this is a lot more of a sane approach for 
the every day person or those new to Gentoo.

On a side note, '--select y' is not necessary as it is implied by '-n'.

One thing I would add as well is that regular 'world' cleaning is good 
practice to have regardless of the above. Every couple of months (on 
average, I don't really keep track) I tend to look at my world file and 
take note of entries that may have found their way there either 
automatically (lack of -1) or something I used to use and no longer 
need. These can be cleaned up with --deselect, followed by --depclean e.g.:

     # emerge --deselect ATOM [ATOM...]
     # emerge -a --depclean

Last time round I only deselected 2-3 packages but that removed about 30 
or so unnecessary dependencies, so pretty chuffed. Disk space is cheap 
these days and there's little reason to be so pedantic, but I tend to 
get quite a satisfying feeling when my system becomes 'leaner' so I do 
it anyway. Having fewer packages installed also helps speed up portage's 
dependency resolution stage during updates which is already an 
incredibly slow process (depending on CPU's single thread performance ofc).

- Victor