nixos-rebuild pollutes current directory with "result" symlink

[peti]

nixos-rebuild boot creates a symlink like

 lrwxrwxrwx 1 root   root    85 Jan 29 10:53 result -> /nix/store/afv0nbqkx5iii9i4k278a0bsdrhbz7m3-nixos-system-mobile-16.03pre75806.77f8f35

in the current directory. The NixOS version is 16.03pre75806.77f8f35 (current unstable channel).

[domenkozar]

Most probably a regression in #12324.

I suspect it broke tests http://hydra.nixos.org/job/nixos/trunk-combined/tested#tabs-constituents but I haven't verified that yet.

[domenkozar]

cc @rickynils

[rickynils]

I look into it.

@domenkozar Does the fact that symlinks are created break tests?

[dezgeg]

Test breakage is not related to this but rather (just got fixed): a581f72

[colemickens]

switch is doing the same.

[Baughn]

For cleanup purposes, this should be relatively safe -- though, probably run it once with echo instead of rm, just to be sure.

nix-store --gc --print-roots | awk '{print $1}' | grep /result$ | sudo xargs rm

It will, of course, also delete any result symlinks you might want to keep. But you knew that.

[ayyess]

nixos-rebuild is making result symlinks on nixos-unstable.

[goodwillcoding]

@abbradar @rickynils
In a related "issue" nixos-rebuild test, build, dry-build, dry-activate also generate the results symlink. To me it seems like the --no-out should be applied there as well so it does not polute the system. I'll issue a PR unless this is somehow a desired behavior.

[wucke13]

@goodwillcoding
There is no such option to nixos-rebuild as --no-out

$ nixos-rebuild --no-out
/run/current-system/sw/bin/nixos-rebuild: unknown option `--no-output'

How shall one prevent nixos-rebuild to create those symlinks?

[Baughn]

That's peculiar. It spell-checked the option... so --no-out exists as an alias for --no-output, but --no-output itself doesn't exist?

[colemickens]

It's another place in general where the Nix tooling just feels inconsistent... It looks like boot/switch were special cased to not drop the out link, rather than making it a proper flag to nixos-rebuild...

[goodwillcoding]

@wucke13 why are you asking me the same question I posed in this issue ... did your read the comments at all?

[wucke13]

@goodwillcoding because I wrongly read your comment as an already working solution, not a suggestion how it should work.

[NonVideri]

This is still around AFAIK. Just got a "result" symlink in my home directory.

[eclairevoyant]

@NonVideri with which subcommand?

[NonVideri]

@eclairevoyant Hard to tell, but probably nixos-rebuild switch, as I mainly use that one.

[eclairevoyant]

If you are able to reproduce on an up-to-date nix install then please create a new issue for it. Also keep in mind the build and build-vm subcommands will create the symlink and that is expcted.

[nixos-discourse]

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

https://discourse.nixos.org/t/copying-custom-edid/31593/12