[chlorion]

You can build binaries on Gentoo and update from the binaries you've built rather than compiling as you go!

You can build binaries for all of the packages that need to be updated by running the normal update command and adding "--buildpkgonly".

[mid-kid]

--buildpkgonly doesn't work for any packages whose dependencies aren't already fully satisfied, including being up-to-date. You simply cannot use --buildpkgonly for a world update save for the very trivial transactions, for which any of what I mentioned isn't a problem anyway.

[chlorion]

I did not realize you were a Gentoo contributor when I first responded!

This is an interesting problem for sure. I don't know enough about portage internals to know whether it could be fixed easily, but it would be very nice to have.

So far I haven't really ran into any consistency issues caused by non-atomic upgrades. The only thing that comes to mind is needing to restart a zsh instance that was running during an upgrade that included it, and Firefox will sometimes tell me it needs to restart!

I have a fairly fast CPU (ryzen 3900x) so the time spent in an inconsistent state is probably much shorter than it is for others, I suppose this is why it's never bothered me before.