🐛 fix(windows): avoid FileNotFoundError in sandboxed environments#422
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gaborbernat merged 3 commits intotox-dev:mainfrom Feb 13, 2026
Merged
🐛 fix(windows): avoid FileNotFoundError in sandboxed environments#422gaborbernat merged 3 commits intotox-dev:mainfrom
gaborbernat merged 3 commits intotox-dev:mainfrom
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SHGetKnownFolderPath with default flags (0) verifies that the target folder physically exists, raising FileNotFoundError in sandboxed Windows environments where USERPROFILE points to a directory without AppData\Local. This was a regression introduced in 4.7.0 when PR tox-dev#380 replaced SHGetFolderPathW with SHGetKnownFolderPath. Passing KF_FLAG_DONT_VERIFY (0x00004000) restores the pre-4.7.0 behavior of returning the expected path without existence checks, matching how the old SHGetFolderPathW API worked. Closes tox-dev#421 Signed-off-by: Bernát Gábor <bgabor8@bloomberg.net>
On Windows, call get_win_folder_via_ctypes with the real Windows API for each CSIDL name to verify integration. Reserve mock-based tests for non-Windows where ctypes Windows bindings don't exist.
Move ctypes.WinDLL mock assignment into _setup_ctypes_mocks so the type: ignore comment only exists in one place that ty can reason about.
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platformdirs 4.7.0 throws
FileNotFoundErroron Windows whenUSERPROFILEpoints to a directory withoutAppData\Local. This regression was introduced in #380, which replacedSHGetFolderPathWwithSHGetKnownFolderPath. 🐛 Unlike the old API,SHGetKnownFolderPathverifies folder existence by default and raises when the directory is missing — breaking sandboxed environments, CI containers, and custom user profiles.The fix passes
KF_FLAG_DONT_VERIFY(0x00004000) as thedwFlagsparameter, tellingSHGetKnownFolderPathto return the expected path without checking whether it physically exists. This restores the 4.6.0 behavior while keeping the modern API. The flag is defined as aFinal[int]module constant since CPython doesn't expose Windows SDK known-folder flags.Closes #421