gh-134451: Converted asyncio.tools.CycleFoundException from dataclass to a regular exception type. (#134513)

Lib/asyncio/tools.py

@@ -13,11 +13,17 @@ class NodeType(Enum):
     TASK = 2
 
 
-@dataclass(frozen=True)
 class CycleFoundException(Exception):
     """Raised when there is a cycle when drawing the call tree."""
-    cycles: list[list[int]]
-    id2name: dict[int, str]
+    def __init__(
+            self,
+            cycles: list[list[int]],
+            id2name: dict[int, str],
+        ) -> None:
+        super().__init__(cycles, id2name)
+        self.cycles = cycles
+        self.id2name = id2name
+
 
 
 # ─── indexing helpers ───────────────────────────────────────────

Misc/NEWS.d/next/Library/2025-05-22-14-12-53.gh-issue-134451.M1rD-j.rst

@@ -0,0 +1 @@
+Converted ``asyncio.tools.CycleFoundException`` from dataclass to a regular exception type.