René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Refreshing doesn't invalidate cached version_info","articleBody":"The `version_info` property of `Git` instances is cached per-instance, while the `git.refresh` function and `Git.refresh` class method modify global state. When `version_info` has been read on a `Git` instance, refreshing affects the behavior of that instance, but does not invalidate the cache, causing the `version_info` property and dynamic `version` method to give inconsistent results even when no changes to environment variables or the filesystem have occurred.\r\n\r\nHere's an example produced on a CentOS 7 system where I have both the system `git` and a newer upstream `git` installed:\r\n\r\n```text\r\nek in 🌐 Eald in GitPython on  main via 🐍 v3.12.1 via 🅒 GitPython\r\n❯ type -a git\r\ngit is /home/ek/bin/git\r\ngit is /usr/bin/git\r\n\r\nek in 🌐 Eald in GitPython on  main via 🐍 v3.12.1 via 🅒 GitPython\r\n❯ git --version\r\ngit version 2.43.0\r\n\r\nek in 🌐 Eald in GitPython on  main via 🐍 v3.12.1 via 🅒 GitPython\r\n❯ /usr/bin/git --version\r\ngit version 1.8.3.1\r\n\r\nek in 🌐 Eald in GitPython on  main via 🐍 v3.12.1 via 🅒 GitPython\r\n❯ python\r\nPython 3.12.1 | packaged by conda-forge | (main, Dec 23 2023, 08:03:24) [GCC 12.3.0] on linux\r\nType \"help\", \"copyright\", \"credits\" or \"license\" for more information.\r\n\u003e\u003e\u003e import git\r\n\u003e\u003e\u003e g1 = git.Git()\r\n\u003e\u003e\u003e g2 = git.Git()\r\n\u003e\u003e\u003e g1.version_info\r\n(2, 43, 0)\r\n\u003e\u003e\u003e git.refresh(\"/usr/bin/git\")\r\n\u003e\u003e\u003e g1.version()\r\n'git version 1.8.3.1'\r\n\u003e\u003e\u003e g2.version()\r\n'git version 1.8.3.1'\r\n\u003e\u003e\u003e g1.version_info\r\n(2, 43, 0)\r\n\u003e\u003e\u003e g2.version_info\r\n(1, 8, 3, 1)\r\n```\r\n\r\nBecause I had accessed `g1.version_info` before refreshing, the stale version information is handed back even after the refresh.\r\n\r\nThis is admittedly consistent with how `version_info` is documented:\r\n\r\nhttps://github.com/gitpython-developers/GitPython/blob/afa575454f85b34800460881cc9c3cd7fe78c8e3/git/cmd.py#L839\r\n\r\nBut it seems to me that the documentation, as currently written, does not prevent it from being surprising. I think that either this should be made clear in the `version_info` property docstring, or the behavior should be changed so that refreshing invalidates all `Git` instances' cached `version_info` properties. I am not sure which is better, because I don't know why `version_info` is cached (and cached per instance).\r\n\r\nThis issue can probably be considered minor. In particular, this does not prevent `FetchInfo.refresh` (which `git.refresh` calls after calling `Git.refresh`) from updating `FetchInfo._flag_map` correctly, because `FetchInfo.refresh` accesses `version_info` on a newly created `Git` instance:\r\n\r\nhttps://github.com/gitpython-developers/GitPython/blob/afa575454f85b34800460881cc9c3cd7fe78c8e3/git/remote.py#L346","author":{"url":"https://github.com/EliahKagan","@type":"Person","name":"EliahKagan"},"datePublished":"2024-02-19T01:54:57.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/1829/GitPython/issues/1829"}