nix: Add support for --keep-going and --keep-failed

[bgamari]

Adds the same flags as were previously used in nix-build.

Fixes #2105.

[dtzWill]

So, honestly this would satisfy all of the uses I have for -k and -K, but even so-- should these shortcuts be specific to nix build? Or maybe pushed up to work for all nix commands that build things?

[dtzWill]

I suppose --keep-going doesn't really make sense, I guess I just wanted to avoid the property we currently enjoy which is that you can often just replace nix log with nix build and such without worrying about which subcommands take which arguments.

And I suppose this should probably be added to documentation?

Also TIL that I can still set those values with --option haha, I always just switched to using nix-build :/.

[bgamari]

Hmm, so apparently --keep-going is already supported. I'm a bit unsure of whether it would be better to:

a. add the short form to the mechanism that currently handles it (which I believe is the Setting class; see globals.hh line 97) and drop this patch, or
b. just drop the long form from this patch

[Ma27]

@edolstra any chance to get this merged? Would be really useful to have this for flakes as well.

[edolstra]

--keep-going and --keep-failed already work because all nix.conf options are also supported as command line flags. So this only adds the -k and -K shortcuts, but I'm not sure whether they're sufficiently commonly used to justify a shortcut.

[stale]

I marked this as stale due to inactivity. → More info

[asymmetric]

@edolstra what's the point of having --keep-going as an option for the nix super-command, rather than only for nix build? Is it used in any other sub-command

I had a hard time finding this option, as I was only searching for it in nix help build.

[thufschmitt]

@edolstra what's the point of having --keep-going as an option for the nix super-command, rather than only for nix build? Is it used in any other sub-command

I guess it also makes sense (at least) for nix shell, nix develop or nix run. And also probably for nix eval --allow-import-from-derivation

[edolstra]

what's the point of having --keep-going as an option for the nix super-command

There is no particular point, but keep-going and keep-failed are nix.conf settings, and all settings have a corresponding command-line option.

[stale]

I marked this as stale due to inactivity. → More info

[Ericson2314]

Perhaps this should be closed, and instead if we want to think about which command should have which options with which shortcuts, #5638 is a better venue.

[Ericson2314]

Closing for the reason above. We have the flags already, and we need better infrastructure if we want to limit the commands that that support these flags in a precise way.

[nixos-discourse]

This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/2023-03-17-nix-team-meeting-minutes-41/26614/1