Windows10: FileChooserButton example sends LF to stderr

[mpilgrem]

I do not know where the problem lies but, on Windows 10, the FileChooserButton example (and only that example) somehow sends LF characters to stderr when the dialog box is first drawn (about 7 or 8 LF characters) and when the buttons are clicked (1 or 2 LF characters).

For example (with the example's dialog box immediately closed once it appears):

>stack exec example -- FileChooserButton 2> temp.txt
>notepad++ temp.txt

yields:

(This is with the package up to commit 1e96813 and built with resolver nightly-2018-12-17 (GHC 8.6.2)).

[mpilgrem]

On Windows 10, I get the same behaviour with resolver lts-13.0 (GHC 8.6.3).

On macOS High Sierra 10.13.6, I do not get the LF character behaviour. (However, when I first click the file chooser button, I get the terminal message "objc[23708]: Class FIFinderSyncExtensionHost is implemented in both /System/Library/PrivateFrameworks/FinderKit.framework/Versions/A/FinderKit (0x7fffb03bacd0) and /System/Library/PrivateFrameworks/FileProvider.framework/OverrideBundles/FinderSyncCollaborationFileProviderOverride.bundle/Contents/MacOS/FinderSyncCollaborationFileProviderOverride (0x108d1bcd8). One of the two will be used. Which one is undefined." Google searches indicate that is an 'Apple problem'.)

[owickstrom]

This is quite strange. Is it only for this example?

Could you maybe try building something using the FileChooserNative widget and see if it behaves the same? See https://hackage.haskell.org/package/gi-gtk-3.0.27/docs/GI-Gtk-Objects-FileChooserNative.html. Not sure that fits well into gi-gtk-declarative at the moment, but you could maybe modify the CSS example and create imperatively in main.

Thanks!