Notes on CPython internals, asyncio, runtime performance, and the bugs I chase. https://deadlovelll.github.io/ SET_ADD trusted the compiler, and PEP 749 quietly handed user code a way to break that trust - Here is a complete Python program that, until last week, crashed every CPython that has annotations lazily evaluated — 3.14, 3.15, and 3.16: __conditional_annotations__ = 0 a: 1 No C extension, no ctypes, no threads. Two lines of plain Python, and the process dies with a signal instead of a... Mon, 10 Aug 2026 00:00:00 +0300 https://deadlovelll.github.io/2026-08-10-conditional-annotations-set-add-crash/ https://deadlovelll.github.io/2026-08-10-conditional-annotations-set-add-crash/ How a task hid from the function whose only job is to list it - The job of asyncio.all_tasks() is to return all active tasks in the event loop. In builds with the GIL disabled, called from a thread other than the one running the loop, it could return fewer tasks than there actually are. But how is this possible? Let’s take a look. The... Mon, 03 Aug 2026 00:00:00 +0300 https://deadlovelll.github.io/2026-08-03-asyncio-all-tasks-free-threading/ https://deadlovelll.github.io/2026-08-03-asyncio-all-tasks-free-threading/