Merge pull request #13452 from NixOS/mergify/bp/2.29-maintenance/pr-13450

libexpr: Fix invalid handling of errors for imported functions (backport #13450)

src/libexpr/eval.cc

@@ -1586,7 +1586,7 @@ void EvalState::callFunction(Value & fun, std::span<Value *> args, Value & vRes,
                                              symbols[i.name])
                                     .atPos(lambda.pos)
                                     .withTrace(pos, "from call site")
-                                    .withFrame(*fun.payload.lambda.env, lambda)
+                                    .withFrame(*vCur.payload.lambda.env, lambda)
                                     .debugThrow();
                         }
                         env2.values[displ++] = i.def->maybeThunk(*this, env2);
@@ -1613,7 +1613,7 @@ void EvalState::callFunction(Value & fun, std::span<Value *> args, Value & vRes,
                                 .atPos(lambda.pos)
                                 .withTrace(pos, "from call site")
                                 .withSuggestions(suggestions)
-                                .withFrame(*fun.payload.lambda.env, lambda)
+                                .withFrame(*vCur.payload.lambda.env, lambda)
                                 .debugThrow();
                         }
                     unreachable();

tests/functional/lang/eval-fail-missing-arg-import.err.exp

@@ -0,0 +1,12 @@
+error:
+       … from call site
+         at /pwd/lang/eval-fail-missing-arg-import.nix:1:1:
+            1| import ./non-eval-trivial-lambda-formals.nix { }
+             | ^
+            2|
+
+       error: function 'anonymous lambda' called without required argument 'a'
+       at /pwd/lang/non-eval-trivial-lambda-formals.nix:1:1:
+            1| { a }: a
+             | ^
+            2|

tests/functional/lang/eval-fail-missing-arg-import.nix

@@ -0,0 +1 @@
+import ./non-eval-trivial-lambda-formals.nix { }

tests/functional/lang/eval-fail-undeclared-arg-import.err.exp

@@ -0,0 +1,13 @@
+error:
+       … from call site
+         at /pwd/lang/eval-fail-undeclared-arg-import.nix:1:1:
+            1| import ./non-eval-trivial-lambda-formals.nix {
+             | ^
+            2|   a = "a";
+
+       error: function 'anonymous lambda' called with unexpected argument 'b'
+       at /pwd/lang/non-eval-trivial-lambda-formals.nix:1:1:
+            1| { a }: a
+             | ^
+            2|
+       Did you mean a?

tests/functional/lang/eval-fail-undeclared-arg-import.nix

@@ -0,0 +1,4 @@
+import ./non-eval-trivial-lambda-formals.nix {
+  a = "a";
+  b = "b";
+}

tests/functional/lang/non-eval-trivial-lambda-formals.nix

@@ -0,0 +1 @@
+{ a }: a