Looks good from here, I wonder, though, if we should just not deprecate it, if it is such a simple function and not doing weird contortions to continue working. What do you think?

Not sure you meant to add the recurseIntoAttrs to this PR?

Oops - yeah the recurseIntoAttrs was meant for a different branch.

I think x86_64-linux is the only instance where we do support building on another system (i686-linux). Otherwise for forceSystem to work you would need remote builders setup or to luck out and get if from the cache. So we definitely don't want Nixpkgs users to have to rely on that. That creates too much of a situation where it works for one person at one time but breaks for everyone else at other times.

I don't have any problem with people using something like this in their own configs but it's hard to separate the two out. I have opened #43692 that will make it a little easier to enforce this kind of thing. This would make it so that you can use the alias locally but on Hydra & OfBorg there will be an evaluation error.

/cc @Ericson2314

I got rid of the warning but will leave it in aliases.nix just to make it clear that it's not something we want people to be using directly as part of all-packages.nix