linkOutputs: rewrite to use script instead of environment variable

Previous implementation had issues when linking large numbers of outputs
due to large environment variables (buildCommand). This patch reimplements
linkOutputs to place the linking commands in a script rather than hold
the commands in an environment variable.

1 files changed, 12 insertions, 12 deletions

diff --git a/default.nix b/default.nix
index 3ec0450..842f55a 100644
--- a/default.nix
+++ b/default.nix
@@ -89,12 +89,8 @@ let
       def = f: defs: attrs: f (defs // attrs);
 
       linkOutputs = x:
-        with lib;
-        nixpkgs.stdenvNoCC.mkDerivation {
-          name = "link-outputs";
-          outputs = [ "out" ] ++ attrNames x;
-          nativeBuildInputs = [ pkgs.perl ];
-          buildCommand =
+        let
+          cmds =
             let
               recurse = x:
                 if x ? type && x.type == "derivation" then
@@ -104,14 +100,18 @@ let
                 else
                   abort "linkOutputs: unsupported type";
               link = dst: src: ''
-                ln -s ${recurse src} $(perl -e 'print $ENV{"${dst}"}') ; ln -s ${
-                  recurse src
-                } $out/${dst}
-              '';
+           ln -s ${recurse src} $(perl -e 'print $ENV{"${dst}"}') ; ln -s ${recurse src} $out/${dst}
+         '';
             in
             ''
-              mkdir $out
-            '' + (concatStringsSep "\n" (mapAttrsToList link x));
+         mkdir $out
+         ${lib.concatStringsSep "\n" (lib.mapAttrsToList link x)}
+       '';
+        in
+        pkgs.stdenvNoCC.mkDerivation {
+          name = "link-outputs";
+          nativeBuildInputs = [ pkgs.perl ];
+          buildCommand = "exec sh ${pkgs.writeScript "make-links" cmds}";
           passthru.linkInputs = x;
         };