From 2bba6a8e13d12caefdbbaa0e201be21ebe4a8d7e Mon Sep 17 00:00:00 2001
From: Richard Lin <elpato25@gmail.com>
Date: Thu, 23 Jul 2026 09:26:09 -0700
Subject: [PATCH 1/3] Plumb error values through generator

---
 edg/core/Generator.py            | 11 ++++++++++-
 edg/core/test_generator_error.py | 23 +++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/edg/core/Generator.py b/edg/core/Generator.py
index 42a7135ef..336c3bd6c 100644
--- a/edg/core/Generator.py
+++ b/edg/core/Generator.py
@@ -142,7 +142,16 @@ def _generated_def_to_proto(
                     self._generator_param_values[param] = param._from_lit(
                         generate_values_map[ref_map[param].SerializeToString()]
                     )
-                self.generate()
+                try:
+                    self.generate()
+                except Exception as e:
+                    params_list_str = ", ".join(
+                        f"{self._name_of_child(param, self, allow_unknown=True)}={self._generator_param_values[param]}"
+                        for param in self._generator_params_list
+                    )
+                    raise RuntimeError(
+                        f"Generator {self.__class__.__name__} with parameters {{{params_list_str}}} raised exception"
+                    ) from e
             elif self._generator is not None:  # legacy generator style
                 fn_args = [
                     arg_param._from_lit(generate_values_map[ref_map[arg_param].SerializeToString()])
diff --git a/edg/core/test_generator_error.py b/edg/core/test_generator_error.py
index da5f5d4c3..622a9d82c 100644
--- a/edg/core/test_generator_error.py
+++ b/edg/core/test_generator_error.py
@@ -6,6 +6,25 @@
 from .HdlUserExceptions import BlockDefinitionError
 
 
+class GeneratorErrorTop(DesignTop):
+    def contents(self) -> None:
+        super().contents()
+        self.generator = self.Block(GeneratorRaises(42, "bad"))
+
+
+class GeneratorRaises(GeneratorBlock):
+    def __init__(self, param: IntLike, str_param: StringLike) -> None:
+        super().__init__()
+        self.param = self.ArgParameter(param)
+        self.str_param = self.ArgParameter(str_param)
+        self.generator_param(self.param, self.str_param)
+
+    @override
+    def generate(self) -> None:
+        super().generate()
+        raise ValueError
+
+
 class BadGeneratorTestCase(unittest.TestCase):
     # These are internal classes to avoid this error case being auto-discovered in a library
 
@@ -29,3 +48,7 @@ def generate(self) -> None:
     def test_non_arg_generator(self) -> None:
         with self.assertRaises(BlockDefinitionError):
             self.InvalidNonArgGeneratorBlock()._elaborated_def_to_proto()
+
+    def test_generator_raises(self) -> None:
+        with self.assertRaises(CompilerCheckError):
+            ScalaCompiler.compile(GeneratorErrorTop)

From 30eb0f2887046cb3ec77927db705558016453bed Mon Sep 17 00:00:00 2001
From: Richard Lin <elpato25@gmail.com>
Date: Thu, 23 Jul 2026 09:28:29 -0700
Subject: [PATCH 2/3] Update test_generator_error.py

---
 edg/core/test_generator_error.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/edg/core/test_generator_error.py b/edg/core/test_generator_error.py
index 622a9d82c..f22d66b7f 100644
--- a/edg/core/test_generator_error.py
+++ b/edg/core/test_generator_error.py
@@ -7,6 +7,7 @@
 
 
 class GeneratorErrorTop(DesignTop):
+    @override
     def contents(self) -> None:
         super().contents()
         self.generator = self.Block(GeneratorRaises(42, "bad"))

From 9af8e0c4091782339ccafb6c5962348cc5c1a962 Mon Sep 17 00:00:00 2001
From: Richard Lin <elpato25@gmail.com>
Date: Thu, 23 Jul 2026 09:35:25 -0700
Subject: [PATCH 3/3] improve

---
 edg/core/Generator.py            | 4 ++--
 edg/core/test_generator_error.py | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/edg/core/Generator.py b/edg/core/Generator.py
index 336c3bd6c..b1a0d6bf2 100644
--- a/edg/core/Generator.py
+++ b/edg/core/Generator.py
@@ -146,11 +146,11 @@ def _generated_def_to_proto(
                     self.generate()
                 except Exception as e:
                     params_list_str = ", ".join(
-                        f"{self._name_of_child(param, self, allow_unknown=True)}={self._generator_param_values[param]}"
+                        f"{self._name_of_child(param, self, allow_unknown=True)}={self._generator_param_values[param]!r}"
                         for param in self._generator_params_list
                     )
                     raise RuntimeError(
-                        f"Generator {self.__class__.__name__} with parameters {{{params_list_str}}} raised exception"
+                        f"Generator {self.__class__.__name__} with parameters {{{params_list_str}}} raised exception: {e!r}"
                     ) from e
             elif self._generator is not None:  # legacy generator style
                 fn_args = [
diff --git a/edg/core/test_generator_error.py b/edg/core/test_generator_error.py
index f22d66b7f..6bba73595 100644
--- a/edg/core/test_generator_error.py
+++ b/edg/core/test_generator_error.py
@@ -53,3 +53,5 @@ def test_non_arg_generator(self) -> None:
     def test_generator_raises(self) -> None:
         with self.assertRaises(CompilerCheckError):
             ScalaCompiler.compile(GeneratorErrorTop)
+        # TODO: inspect the exception, note that it is consumed by the Scala compiler
+        # and not summarized in the CompilerCheckError