Emerge/emerge_without_internet

No internet/ethernet, still want to emerge? It's possible. To make life easer for yourself, do not use the default locations of /usr/portage/distfiles and /usr/portage/packages - redefine the locations in /etc/make.conf and do any moving of contents that is required (also see MAN make.conf).

Now, it's quite safe to delete /usr/portage when you update the portage tree with a new snapshot. Your downloaded source files and any binary packages you may have made will be preserved.

Getting started

Get a new, up-to-date portage snapshot, delete your /usr/portage, and untar your new snapshot to /usr, just as the install guide tells you. Now do an emerge --regen && emerge --metadata. You now have an updated portage tree in place.

Users needing a few odds and ends to get networking or Wifi operating start here. Now you can do --pretend emerges against your new portage tree.

emerge <target> -fp

will provide you with a list of URLs you need to fetch to be able to run the emerge for real. Here, <target> can include any other flags to emerge, like -u, -D, -N that affect what is built. See man emerge.

Fetch all the required URLs and copy them to wherever you redefined /usr/portage/distfiles to be. Now you have everything in place to run

emerge <target>

for real.