From f2ce5e561a8a3c94c9f0cbb273f3feb3756d1e3f Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Sat, 22 Nov 2025 13:46:46 +0000
Subject: [PATCH] [ty] Improve concise diagnostics for invalid exceptions when
 a user catches a tuple of objects (#21578)

---
 crates/ty_python_semantic/src/types/diagnostic.rs    | 5 +++++
 crates/ty_python_semantic/src/types/infer/builder.rs | 7 ++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/crates/ty_python_semantic/src/types/diagnostic.rs b/crates/ty_python_semantic/src/types/diagnostic.rs
index a91048f54d..163e496107 100644
--- a/crates/ty_python_semantic/src/types/diagnostic.rs
+++ b/crates/ty_python_semantic/src/types/diagnostic.rs
@@ -2436,6 +2436,7 @@ pub(super) fn report_possibly_missing_attribute(
 pub(super) fn report_invalid_exception_tuple_caught<'db, 'ast>(
     context: &InferContext<'db, 'ast>,
     node: &'ast ast::ExprTuple,
+    node_type: Type<'db>,
     invalid_tuple_nodes: impl IntoIterator<Item = (&'ast ast::Expr, Type<'db>)>,
 ) {
     let Some(builder) = context.report_lint(&INVALID_EXCEPTION_CAUGHT, node) else {
@@ -2443,6 +2444,10 @@ pub(super) fn report_invalid_exception_tuple_caught<'db, 'ast>(
     };
 
     let mut diagnostic = builder.into_diagnostic("Invalid tuple caught in an exception handler");
+    diagnostic.set_concise_message(format_args!(
+        "Cannot catch object of type `{}` in an exception handler",
+        node_type.display(context.db())
+    ));
 
     for (sub_node, ty) in invalid_tuple_nodes {
         let span = context.span(sub_node);
diff --git a/crates/ty_python_semantic/src/types/infer/builder.rs b/crates/ty_python_semantic/src/types/infer/builder.rs
index 3ffbd12425..ed1042e04f 100644
--- a/crates/ty_python_semantic/src/types/infer/builder.rs
+++ b/crates/ty_python_semantic/src/types/infer/builder.rs
@@ -3053,7 +3053,12 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                         .iter()
                         .map(|(index, ty)| (&tuple.elts[*index], **ty));
 
-                    report_invalid_exception_tuple_caught(&self.context, tuple, invalid_elements);
+                    report_invalid_exception_tuple_caught(
+                        &self.context,
+                        tuple,
+                        node_ty,
+                        invalid_elements,
+                    );
                 } else {
                     report_invalid_exception_caught(&self.context, node, node_ty);
                 }