fix[lang]: show user error in error map

tests/unit/compiler/test_source_map.py

@@ -97,8 +97,18 @@ def update_foo():
     self.foo += 1
     """
     error_map = compile_code(code, output_formats=["source_map"])["source_map"]["error_map"]
-    assert "safeadd" in list(error_map.values())
-    assert "fallback function" in list(error_map.values())
+    assert "safeadd" in error_map.values()
+    assert "fallback function" in error_map.values()
+
+
+def test_error_map_with_user_error():
+    code = """
+@external
+def foo():
+    raise "some error"
+    """
+    error_map = compile_code(code, output_formats=["source_map"])["source_map"]["error_map"]
+    assert "user revert with reason" in error_map.values()
 
 
 def test_compress_source_map():

vyper/codegen/stmt.py

@@ -155,7 +155,10 @@
             ir_node = revert_seq
         else:
             ir_node = ["if", ["iszero", test_expr], revert_seq]
-        return IRnode.from_list(ir_node, error_msg="user revert with reason")
+
+        ir_node = IRnode.from_list(ir_node)
+        ir_node.set_error_msg("user revert with reason")
+        return ir_node
 
     def parse_Assert(self):
         test_expr = Expr.parse_value_expr(self.stmt.test, self.context)