Commit 5c30512e authored by Alyssa Ross's avatar Alyssa Ross Committed by Valentin Gagarin
Browse files

doc/using/overrides: manage package option expectations 



We haven't been good at managing expectations about this, so let's
tell people what level of support they can expect.  I think the place
people are most likely to see it is the place where they learn about
overriding in the first place, so I've added it here.

Co-authored-by: default avatarValentin Gagarin <valentin@gagarin.work>
parent 639a4a70

doc/using/overrides.chapter.md

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@@ -40,6 +40,13 @@ import pkgs.path { overlays = [ (self: super: { 


In the first example, `pkgs.foo` is the result of a function call with some default arguments, usually a derivation. Using `pkgs.foo.override` will call the same function with the given new arguments.



Many packages, like the `foo` example above, provide package options with default values in their arguments, to facilitate overriding.

Because it's not usually feasible to test that packages build with all combinations of options, you might find that a package doesn't build if you override options to non-default values.



Package maintainers are not expected to fix arbitrary combinations of options.

If you find that something doesn't work, please submit a fix, ideally with a regression test.

If you want to ensure that things keep working, consider [becoming a maintainer](https://github.com/NixOS/nixpkgs/tree/master/maintainers) for the package.



## &lt;pkg&gt;.overrideAttrs {#sec-pkg-overrideAttrs}



The function `overrideAttrs` allows overriding the attribute set passed to a `stdenv.mkDerivation` call, producing a new derivation based on the original one. This function is available on all derivations produced by the `stdenv.mkDerivation` function, which is most packages in the nixpkgs expression `pkgs`.