Commit graph

7 commits

Author SHA1 Message Date
Eelco Dolstra 62a6eeb1f3 Make the Nix search path declarative
Nix search path lookups like <nixpkgs> are now desugared to ‘findFile
nixPath <nixpkgs>’, where ‘findFile’ is a new primop. Thus you can
override the search path simply by saying

  let
    nixPath = [ { prefix = "nixpkgs"; path = "/my-nixpkgs"; } ];
  in ... <nixpkgs> ...

In conjunction with ‘scopedImport’ (commit
c273c15cb1), the Nix search path can be
propagated across imports, e.g.

  let

    overrides = {
      nixPath = [ ... ] ++ builtins.nixPath;
      import = fn: scopedImport overrides fn;
      scopedImport = attrs: fn: scopedImport (overrides // attrs) fn;
      builtins = builtins // overrides;
    };

  in scopedImport overrides ./nixos
2014-05-26 17:02:22 +02:00
Eelco Dolstra 39d72640c2 Ensure that -I flags get included in nixPath
Also fixes #261.
2014-05-26 16:52:31 +02:00
Eelco Dolstra a8edf185a9 Add constant ‘nixPath’
It contains the Nix expression search path as a list of { prefix, path
} sets, e.g.

  [ { path = "/nix/var/nix/profiles/per-user/root/channels/nixos"; prefix = ""; }
    { path = "/etc/nixos/configuration.nix"; prefix = "nixos-config"; }
    { path = "/home/eelco/Dev/nix/inst/share/nix/corepkgs"; prefix = "nix"; }
  ]
2014-05-26 14:55:47 +02:00
Eelco Dolstra 48cea0d01e * Refactoring: Get rid of a few subdirectories in corepkgs/, and some
other simplifications.
* Use <nix/...> to locate the corepkgs.  This allows them to be
  overriden through $NIX_PATH.
* Use bash's pipefail option in the NAR builder so that we don't need
  to create a temporary file.
2012-01-03 00:16:29 +00:00
Eelco Dolstra 07340b8be7 * Add the Nix corepkgs to the end of the search path. This makes it
possible for other Nix expressions to use corepkgs (mostly useful
  for the buildenv function).
2011-08-06 18:23:38 +00:00
Eelco Dolstra c7101dac0b * Allow redirections in search path entries. E.g. if you have a
directory

    /home/eelco/src/stdenv-updates

  that you want to use as the directory for import such as

    with (import <nixpkgs> { });

  then you can say

    $ nix-build -I nixpkgs=/home/eelco/src/stdenv-updates
2011-08-06 17:48:57 +00:00
Eelco Dolstra 1ecc97b6bd * Add a Nix expression search path feature. Paths between angle
brackets, e.g.

    import <nixpkgs/pkgs/lib>

  are resolved by looking them up relative to the elements listed in
  the search path.  This allows us to get rid of hacks like

    import "${builtins.getEnv "NIXPKGS_ALL"}/pkgs/lib"

  The search path can be specified through the ‘-I’ command-line flag
  and through the colon-separated ‘NIX_PATH’ environment variable,
  e.g.,

    $ nix-build -I /etc/nixos ...

  If a file is not found in the search path, an error message is
  lazily thrown.
2011-08-06 16:05:24 +00:00