Release v4.0.1 (#1286)

Author: alexmojaki

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Release Notes
 
+## [v4.0.1] (2025-07-31)
+
+* Handle cyclic references in exceptions by @alexmojaki in [#1284](https://github.com/pydantic/logfire/pull/1284)
+* Support OpenTelemetry 1.36.0 by @alexmojaki in [#1285](https://github.com/pydantic/logfire/pull/1285)
+
 ## [v4.0.0] (2025-07-22)
 
 **BREAKING CHANGES**:
@@ -809,3 +814,4 @@ First release from new repo!
 [v3.24.2]: https://github.com/pydantic/logfire/compare/v3.24.1...v3.24.2
 [v3.25.0]: https://github.com/pydantic/logfire/compare/v3.24.2...v3.25.0
 [v4.0.0]: https://github.com/pydantic/logfire/compare/v3.25.0...v4.0.0
+[v4.0.1]: https://github.com/pydantic/logfire/compare/v4.0.0...v4.0.1

logfire-api/logfire_api/_internal/utils.pyi

@@ -129,7 +129,7 @@ def platform_is_emscripten() -> bool:
 
     Threads cannot be created on Emscripten, so we need to avoid any code that creates threads.
     """
-def canonicalize_exception_traceback(exc: BaseException) -> str:
+def canonicalize_exception_traceback(exc: BaseException, seen: set[int] | None = None) -> str:
     """Return a canonical string representation of an exception traceback.
 
     Exceptions with the same representation are considered the same for fingerprinting purposes.

logfire-api/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "logfire-api"
-version = "4.0.0"
+version = "4.0.1"
 description = "Shim for the Logfire SDK which does nothing unless Logfire is installed"
 authors = [
     { name = "Pydantic Team", email = "[email protected]" },

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "logfire"
-version = "4.0.0"
+version = "4.0.1"
 description = "The best Python observability tool! 🪵🔥"
 requires-python = ">=3.9"
 authors = [