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Bug
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Resolution: Fixed
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Low
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None
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None
E.g. when I run "MusicBrainz-Picard-2.9.0b3.exe -h" the mouse pointer first briefly changes to a loading animation and then an error dialog appears:
Failed to execute script 'tagger' due to unhandled exception: 'NoneType' object has no attribute 'write' Traceback (most recent call last): File "tagger.py", line 17, in <module> File "tagger.py", line 1440, in main File "tagger.py", line 1398, in process_picard_args File "argparse.py", line 1768, in parse_args File "argparse.py", line 1800, in parse_known_args File "argparse.py", line 2006, in _parse_known_args File "argparse.py", line 1946, in consume_optional File "argparse.py", line 1874, in take_action File "argparse.py", line 1044, in __call__ File "argparse.py", line 2494, in print_help File "argparse.py", line 2500, in _print_message AttributeError: 'NoneType' object has no attribute 'write'
However if use an option that opens the GUI there is no error (but no command line output either for e.g. "-d")
[PICARD-2688] Windows: Portable version crashes when launched with "-h"
We can probably avoid raising that exceptions, but we likely can't do anything about the missing output.
In general Windows strictly distinguishes between GUI and CLI applications. Essentially GUI applications can create Windows, but they don't have a console attached. CLI applications have a console attached, but can't create Windows.
That means naturally that when starting a GUI application from console you won't see any output there. For the normal installer package of Picard we do some shenanigans to allow console output anyway (https://github.com/metabrainz/picard/blob/master/scripts/pyinstaller/win-startup-hook.py#L28-L34). This way launching Picard on Windows from a console works very similar to other platforms. Not entirely, though, as e.g. the console does not block while Picard is running. Windows still detaches the launched application from the console, but we trick it into writing output to the console anyway.
For some reason this does not work for the onefile package. I investigated this a bit when I implemented the console workaround. I don't know the exact reason, but it seems to be related to how launching the application works in the onefile case, where it first has to extract all the files into a temporary folder before actually launching the application itself.
It looks like similar to https://github.com/microsoft/playwright-python/issues/1148
Basically sys.stderr = None in the reported case.
That's related to pyinstaller options used to build the package -> https://pyinstaller.org/en/stable/usage.html#windows-and-mac-os-x-specific-options
See code changes in pull request #2259 submitted by phw.