From 83b485e44a481d192b660eb724297ebcfe6af416 Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Sat, 24 Jul 2021 14:42:03 -0700
Subject: [PATCH] Fix ParamSpec semanal issue

Recreating equivalent ParamSpecExpr objects causes the equality check in
is_same_symbol in add_symbol_table_node to fail, causing a name already
defined error.
---
 mypy/semanal.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/mypy/semanal.py b/mypy/semanal.py
index 15036e065265..1c39aa0de256 100644
--- a/mypy/semanal.py
+++ b/mypy/semanal.py
@@ -3172,11 +3172,15 @@ def process_paramspec_declaration(self, s: AssignmentStmt) -> bool:
         # PEP 612 reserves the right to define bound, covariant and contravariant arguments to
         # ParamSpec in a later PEP. If and when that happens, we should do something
         # on the lines of process_typevar_parameters
-        paramspec_var = ParamSpecExpr(
-            name, self.qualified_name(name), self.object_type(), INVARIANT
-        )
-        paramspec_var.line = call.line
-        call.analyzed = paramspec_var
+
+        if not call.analyzed:
+            paramspec_var = ParamSpecExpr(
+                name, self.qualified_name(name), self.object_type(), INVARIANT
+            )
+            paramspec_var.line = call.line
+            call.analyzed = paramspec_var
+        else:
+            assert isinstance(call.analyzed, ParamSpecExpr)
         self.add_symbol(name, call.analyzed, s)
         return True