trivial-builders: merge passAsFile with env in runCommand'

Previously it was awkward to use the runCommand-variants with
passAsFile as a double definition of passAsFile would potentially
break runCommand: passAsFile would overwrite the previous definition,
defeating the purpose of setting it in runCommand in the first place.
This is now fixed by concatenating the [ "buildCommand" ] list with
one the one from env, if present.

Adjust buildEnv where passAsFile = null; was passed in some cases,
breaking evaluation since it'd evaluate to [ "buildCommand" ] ++ null.

1 files changed, 3 insertions, 2 deletions

diff --git a/pkgs/build-support/trivial-builders.nix b/pkgs/build-support/trivial-builders.nix
index eab5366e1839e..8759a67f4ea11 100644
--- a/pkgs/build-support/trivial-builders.nix
+++ b/pkgs/build-support/trivial-builders.nix
@@ -6,13 +6,14 @@ let
     stdenv.mkDerivation ({
       name = lib.strings.sanitizeDerivationName name;
       inherit buildCommand;
-      passAsFile = [ "buildCommand" ];
+      passAsFile = [ "buildCommand" ]
+        ++ (env.passAsFile or []);
     }
     // (lib.optionalAttrs runLocal {
           preferLocalBuild = true;
           allowSubstitutes = false;
        })
-    // env);
+    // builtins.removeAttrs env [ "passAsFile" ]);
 
 in