René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"ReadTimeoutError doesn't pickle / maintain the str parsing","articleBody":"### Subject\n\nWhen using urllib3 inside of multiprocessing, python often uses pickle to send exceptions and other data from the child to the parent. If ReadTimeoutError is raised inside a multiprocess, it gets pickle, but loses most of its context in route back to the parent process.\n\n### Environment\n\nDescribe your environment.\nAt least, paste here the output of:\n\n```python\n\u003e\u003e\u003e import platform\n\u003e\u003e\u003e import ssl\n\u003e\u003e\u003e import urllib3\n\u003e\u003e\u003e\n\u003e\u003e\u003e print(\"OS\", platform.platform())\nprint(\"Python\", platform.python_version())\nprint(ssl.OPENSSL_VERSION)\nprint(\"urllib3\", urllib3.__version__)\nOS macOS-15.3.1-x86_64-i386-64bit\n\u003e\u003e\u003e print(\"Python\", platform.python_version())\nPython 3.10.14\n\u003e\u003e\u003e print(ssl.OPENSSL_VERSION)\nOpenSSL 1.1.1w  11 Sep 2023\n\u003e\u003e\u003e print(\"urllib3\", urllib3.__version__)\nurllib3 2.3.0\n```\n\n### Steps to Reproduce\n\nA simple and isolated way to reproduce the issue. A code snippet would be great.\n\n```\nIn [1]: import urllib3\n   ...: import pickle\n\nIn [2]: ex = urllib3.exceptions.ReadTimeoutError('connection pool', 'my url', 'the message with more context')\n\nIn [3]: print(ex)\nconnection pool: the message with more context\n\nIn [4]: print(pickle.loads(pickle.dumps(ex)))\nNone: None\n```\n\n### Expected Behavior\n\nI understand not pickling the connection pool but optimally the error message should at least include the originally given message after pickling.\n\n### Actual Behavior\n\nSee the steps to reproduce. The string version of the exception winds up being a confusing: `None: None`\n","author":{"url":"https://github.com/csm10495","@type":"Person","name":"csm10495"},"datePublished":"2025-02-27T00:29:38.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/3567/urllib3/issues/3567"}