From cee35739ff0800f5738ecbedb43c356a2f06c96f Mon Sep 17 00:00:00 2001
From: Bas van Dijk <v.dijk.bas@gmail.com>
Date: Sun, 23 Jun 2019 21:39:29 +0200
Subject: [PATCH] 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 $PATH
...
/nix/store/yifq4bikf7m07160bpia7z48ciqddbfi-tree-1.8.0/bin:
/nix/store/vhxqk81234ivqw1a7j200a1c69k8mywi-htop-2.2.0/bin:
/nix/store/n9vm3m58y1n3rg3mlll17wanc9hln58k-hello-2.10/bin
...
Previously the order was:
/nix/store/n9vm3m58y1n3rg3mlll17wanc9hln58k-hello-2.10/bin
/nix/store/vhxqk81234ivqw1a7j200a1c69k8mywi-htop-2.2.0/bin:
/nix/store/yifq4bikf7m07160bpia7z48ciqddbfi-tree-1.8.0/bin:
I think the new order makes more sense because it allows to override
the PATH in the outermost mkShell.
---
pkgs/build-support/mkshell/default.nix | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/pkgs/build-support/mkshell/default.nix b/pkgs/build-support/mkshell/default.nix
index 698974590880..a70dc0390cb5 100644
--- a/pkgs/build-support/mkshell/default.nix
+++ b/pkgs/build-support/mkshell/default.nix
@@ -11,13 +11,8 @@
...
}@attrs:
let
- mergeInputs = name:
- let
- op = item: sum: sum ++ item."${name}" or [];
- nul = [];
- list = [attrs] ++ inputsFrom;
- in
- lib.foldr op nul list;
+ mergeInputs = name: lib.concatLists (lib.catAttrs name
+ ([attrs] ++ inputsFrom));
rest = builtins.removeAttrs attrs [
"inputsFrom"