stdin, stdout, stderr when GUI app is launched from command line

Takashi Yano
Thu May 4 21:59:43 GMT 2023

On Thu, 4 May 2023 15:10:03 +0000
"Kacvinsky, Tom" wrote:
> I have a Windows GUI app that I have set to run with Windows Application Verifier.
> In particular, I have App verifier set to trigger on invalid handle exceptions (code is
> 0xC0000008).  When the application is run from the Cygwin console, it faults with
> an invalid handle three times.  I can continue past them in windbg (or gdb for that
> matter) and the application launches.  I think it is curious the invalid handle exception
> occurs three times - is it stdin, stdout and stderr that App Verifier thinks are invalid
> handles?  My hunch is yes, they are.
> I did notice that if I run the GUI use run.exe, as in "run guiapp.exe", the application
> launches with no invalid handle exceptions.
> I am using this version of Cygwin 64
> vapkay@US05117NB ~ $ cygcheck -V
> cygcheck (cygwin) 3.1.7
> But it also happens with 3.4.6
> Is this to be expected with a GUI app when run under a Cygwin console?  I've never
> seen it until I ran with App Verifier.  The GUI application is a Qt app.  I check the Qt
> version we're using for use of and I don't see anything in the WinMain what would
> have to do with reading/writing to the standard IO file descriptors.
> Any ideas?

I cannot reproduce your problem with cygwin 3.4.6.
Could you please provide detailed steps?

Takashi Yano <>

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