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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"socket.CAN_RAW_ERR_FILTER is not defined in Python 3.11 and later","articleBody":"# Bug report\n\n### Bug description:\n\nWhen trying to use `socket.CAN_RAW_ERR_FILTER` on a Debian bookworm system, running Python 3.11, an `AttributeError` is raised. This is because the value is no longer defined in `socket.py`/`_socket`.\n\nI have also tested in Python 3.13.1, and the issue is still present there.\n\nTypical usage of the value:\n```python\nimport socket\nsock = socket.socket(socket.AF_CAN, socket.SOCK_RAW | socket.SOCK_NONBLOCK, socket.CAN_RAW)\nsock.bind((interface_name,))\nsock.setsockopt(socket.SOL_CAN_RAW, socket.CAN_RAW_ERR_FILTER, socket.CAN_ERR_MASK)\n```\n\nMinimized reproduction:\n```python\nimport socket\nprint(socket.CAN_RAW_ERR_FILTER)\n```\n\nActual output:\n```\nTraceback (most recent call last):\n  File \"\u003cpython-input-1\u003e\", line 1, in \u003cmodule\u003e\n    print(socket.CAN_RAW_ERR_FILTER)\n          ^^^^^^^^^^^^^^^^^^^^^^^^^\nAttributeError: module 'socket' has no attribute 'CAN_RAW_ERR_FILTER'. Did you mean: 'CAN_RAW_FILTER'?\n```\n\nExpected output (taken from Python 3.10.12):\n```\n2\n```\n\nInvestigating the issue, it seems to have been introduced in Python 3.11 by the following PR: https://github.com/python/cpython/pull/30066\nIn this PR, adding the `CAN_RAW_ERR_FILTER` value to `socket` was made conditional on defining `CAN_RAW_ERR_FILTER` during compilation. However, no change was made to actually define the value, thus it is never compiled for compatible systems.\n\nNote that the `CAN_RAW_ERR_FILTER` value is coming from `linux/can/raw.h` where is it defined as an `enum` value. Thus it will not be used by the C/C++ preprocessor to evaluate the `#ifdef CAN_RAW_ERR_FILTER` in `Modules/socketmodule.c`.\n\nExcerpt of relevant `raw.h` file from Debian Bookworm:\n```c\n/* for socket options affecting the socket (not the global system) */\n\nenum {\n\tCAN_RAW_FILTER = 1,\t/* set 0 .. n can_filter(s)          */\n\tCAN_RAW_ERR_FILTER,\t/* set filter for error frames       */\n\tCAN_RAW_LOOPBACK,\t/* local loopback (default:on)       */\n\tCAN_RAW_RECV_OWN_MSGS,\t/* receive my own msgs (default:off) */\n\tCAN_RAW_FD_FRAMES,\t/* allow CAN FD frames (default:off) */\n\tCAN_RAW_JOIN_FILTERS,\t/* all filters must match to trigger */\n\tCAN_RAW_XL_FRAMES,\t/* allow CAN XL frames (default:off) */\n};\n```\n\n### CPython versions tested on:\n\n3.11, 3.13\n\n### Operating systems tested on:\n\nLinux\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-129721\n* gh-132702\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/jbogers","@type":"Person","name":"jbogers"},"datePublished":"2025-02-06T09:22:10.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/129719/cpython/issues/129719"}