René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Messed plugin config list order","articleBody":"Hi!\n\n**TL;DR**\n\nI think that merge_dicts implementation in `_utils.py` is wrong:\n\n```py\ndef merge_dicts(dict_a, dict_b):\n    \"\"\"Recursively merge dictionary b into dictionary a.\n\n    If override_nones is True, then\n    \"\"\"\n\n    def _merge_dicts_(a, b):\n        for key in set(a.keys()).union(b.keys()):\n            if key in a and key in b:\n                if isinstance(a[key], dict) and isinstance(b[key], dict):\n                    yield (key, dict(_merge_dicts_(a[key], b[key])))\n                elif isinstance(a[key], list) and isinstance(b[key], list):\n                    yield (key, list(set(a[key] + b[key]))) # \u003c--- this line here is wrong\n                elif b[key] is not None:\n                    yield (key, b[key])\n                else:\n                    yield (key, a[key])\n            elif key in a:\n                yield (key, a[key])\n            elif b[key] is not None:\n                yield (key, b[key])\n\n    return dict(_merge_dicts_(dict_a, dict_b))\n```\n\nBy converting the list to a set, it not only gets rid of the duplicates, but also messes up the list order unpredictably. Replacing `set()` with `OrderedDict.fromkeys()` seems to fix the issue described in detail below.\n\n----\n\nI'm using pylsp v1.13.1 with pylsp_mypy v0.7.0. (The whole LSP is run by Emacs v30.1 via eglot, but this probably doesn't matter.) And I noticed the following strange behavior, which I can't really put my finger on yet.\n\nWhen pylsp invokes pylsp_mypy, it uses the following configuration:\n\n```\n[stderr]  2025-10-08 12:21:46,942 CEST - INFO - pylsp.config.config - Updated settings to {'plugins': {'jedi': {'environment': '/home/david/pyproj/.venv'}, 'ruff': {'executable': '/home/david/pyproj/.venv/bin/ruff'}, 'pylsp_mypy': {'overrides': ['--python-executable', '/home/david/pyproj/.venv/bin/python', True]}, 'flake8': {'executable': None}, 'pylint': {'executable': None}}}\n```\n\nNote the `overrides` list. The next log line after this, however, is this:\n\n```\n[stderr]  2025-10-08 12:21:47,475 CEST - INFO - pylsp_mypy.plugin - lint settings = {'overrides': [True, '/home/david/pyproj/.venv/bin/python', '--python-executable']} document.path = /home/david/pyproj/src/pyproj/__init__.py is_saved = False\n```\n\nNote how the `overrides` list is in reverse order. And right enough, mypy refuses to run:\n\n```\nerror: argument --python-executable: expected one **argument**\n```\n\nI also noticed that it's not always reverse, the order seems to be pretty random. Sometimes it's ok and works, other times, it's messed up.","author":{"url":"https://github.com/dhanak","@type":"Person","name":"dhanak"},"datePublished":"2025-10-08T10:51:16.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/677/python-lsp-server/issues/677"}