51 Matching Annotations
  1. Nov 2019
    1. { packageOverrides = pkgs: rec { foo = pkgs.foo.override { ... }; }; }

      Why is rec needed here, and not in the example under 2.6.1?

      Based on what I saw with other examples, rec is usually included when a_package.override is used inside packageOverrides. But why?

    1. 3. Deployment as Memory Management

      The entire chapter 3 is worth reading. Great resource on what a package (or more broadly, a component) is in regards to Nix.

      Specifically "3.1 What is a component?"

    1. packages

      There is no officially prescribed reading order of the Nix manuals, but it's safe to say that one should start this, the Nix manual. Then it would be prudent to briefly describe what a package is in the context of Nix and/or (at east) link to the definition.

      I like how Dolstra's thesis has an entire section on the topic (that is, on the more general concept of components).

    2. You can have multiple versions or variants of a package installed at the same time.

      It is clear now that there can be multiple versions of the same package in the store, but how does one call them (e.g., if is an executable application)? Simply by using the full Nix store path (and create and manage one's own symlinks, with stow or manually)??

    1. haskell-overridez is a tool and library of nix functions that simplify the use of overrides while developing haskell projects with nixpkgs.

  2. Oct 2019
    1. fixed-point

      "fixed-point", "fix point" seems to be most important concept in Nix, because overrides, overridePackages, overlays are built using it.

    2. Overlays
    3. buildEnv
    4. stdenv.lib.licenses

      Find out where stdenv.lib functions are documented.

    5. builtins.elem

      builtins.elem x xs

      Return true if a value equal to x occurs in the list xs, and false otherwise.

    6. builtins.parseDrvName

      builtins.parseDrvName s

      Split the string s into a package name and version. The package name is everything up to but not including the first dash followed by a digit, and the version is everything following that dash. The result is returned in a set { name, version }. Thus, builtins.parseDrvName "nix-0.12pre12876" returns { name = "nix"; version = "0.12pre12876"; }.

    7. This option is a function which accepts a package as a parameter, and returns a boolean. The following example configuration accepts a package and always returns false: { allowUnfreePredicate = (pkg: false); }

      What is a package in this context? That is, the callback's pkg parameter. Is it a derivation?

      If I understood it correctly, whenever referencing other packages as inputs, those are actually derivations, that are just attribute sets.

  3. Jul 2019
  4. Jun 2019
  5. Dec 2018
  6. Nov 2018
  7. Oct 2018
  8. Sep 2018
  9. Jul 2018
  10. Jun 2018
  11. Dec 2017