mkshell: improve mergeInputs

mergeInputs is now simply defined in terms of `concatLists` and
`catAttrs` instead of a more complicated `foldr`.

Note that the order of PATH has also changed. For example running the
following with nix-shell:

  let
    pkgs = import <nixpkgs> {};

    shell1 = pkgs.mkShell {
      buildInputs = [ pkgs.htop ];
    };

    shell2 = pkgs.mkShell {
      buildInputs = [ pkgs.hello ];
    };

    shell3 = pkgs.mkShell {
      inputsFrom = [ shell1 shell2 ];
      buildInputs = [ pkgs.tree ];
    };

  in shell3

Results in the following PATH:

$ echo $PATH
...
/nix/store/yifq4bikf7m07160bpia7z48ciqddbfi-tree-1.8.0/bin:
/nix/store/vhxqk81234ivqw1a7j200a1c69k8mywi-htop-2.2.0/bin:
/nix/store/n9vm3m58y1n3rg3mlll17wanc9hln58k-hello-2.10/bin
...

Previously the order was:

/nix/store/n9vm3m58y1n3rg3mlll17wanc9hln58k-hello-2.10/bin
/nix/store/vhxqk81234ivqw1a7j200a1c69k8mywi-htop-2.2.0/bin:
/nix/store/yifq4bikf7m07160bpia7z48ciqddbfi-tree-1.8.0/bin:

I think the new order makes more sense because it allows to override
the PATH in the outermost mkShell.

This commit is contained in:

Bas van Dijk

2019-06-23 22:20:10 +02:00

parent 76ef802d3d

commit cee35739ff

1 changed files with 2 additions and 7 deletions

									
										pkgs/build-support/mkshell/default.nix
									
		+2
		-7
	
												View File
												
					@@ -11,13 +11,8 @@

					  ...

					  ...

					}@attrs:

					}@attrs:

					let

					let

					  mergeInputs = name:

					  mergeInputs = name: lib.concatLists (lib.catAttrs name

					    let

					    ([attrs] ++ inputsFrom));

					      op = item: sum: sum ++ item."${name}" or [];

					      nul = [];

					      list = [attrs] ++ inputsFrom;

					    in

					      lib.foldr op nul list;

					  rest = builtins.removeAttrs attrs [

					  rest = builtins.removeAttrs attrs [

					    "inputsFrom"

					    "inputsFrom"