The most likely culprit would be OS.File not handling properly Unicode names depending on the file system. If I recall correctly, OS.File uses the default translation of strings provided by js-ctypes (I think it's UTF-8), which may not may to what the file system is using. Could this explain the issue here?
Bug 1549386 Comment 8 Edit History
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The most likely culprit would be OS.File not handling properly Unicode names depending on the file system. If I recall correctly, OS.File uses the default translation of strings provided by js-ctypes (I think it's UTF-8), which may not may to what the file system is using. Could this explain the issue here? If that's the issue, I'm unfortunately not sure how to fix it.