Failed assertion dialog box

[Duncan Roe]

On Fri, Nov 13, 2020 at 11:21:12PM -0500, cygwin wrote:
> On Fri, Nov 13, 2020 at 10:45 PM Duncan Roe <duncan_roe@optusnet.com.au>
> wrote:
>
> > Hi William,
> >
> > On Fri, Nov 13, 2020 at 12:27:57PM -0500, cygwin wrote:
> > > I've run into a problem running a collection of tests under Cygwin and I
> > > wonder if anyone can suggest a way around it.
> > >
> > > The problem occurs when a program being run fails a C/C++ runtime
> > > assertion. Ordinarily, this just writes an error message on stderr and
> > > aborts. Under Cygwin, however, if both stdin and stderr are redirected to
> > > files, the program instead pops up a dialog box that must be
> > interactively
> > > dismissed before the failed program will exit - holding up all the tests
> > > that follow it.
> > >
> > > Specifically, if I have the following as assert.cpp:
> > >
> > >     #include <assert.h>
> > >     int main() {
> > >       assert(false);
> > >     }
> > >
> > > and say
> > >
> > >     gcc assert.cpp
> > >     ./a.exe < /dev/null > output 2>&1
> > >
> > > I get an error dialog box saying
> > >
> > >     Failed assertion
> > >         false
> > >     at line 3 of file assert.cpp
> > >     in function int main()
> > >
> > > If I omit either the stdin or the stderr redirection, the program behaves
> > > as desired with no dialog box.
> > >
> > > Is there an environment setting or compiler command-line option I can
> > give
> > > to suppress the dialog box and always just write a message to stderr and
> > > abort? Thanks for any insights.
> >
> > Your example WFFM, (Cygwin64, gcc 10.2.0, everything else also up to date).
> >
> > Do you still see this behaviour if you run the installer?
> >
>
> Thanks for your reply; unfortunately, yes, it does. I had refreshed
> the installation fairly recently, and running the installer only updated a
> few things, not cygwin.dll and not gcc; my installation is the same as
> yours. I've tried it with three different shells (tcsh, bash, mksh) and
> with both gcc and clang, and all have the same behavior. (Interestingly, if
> I compile the example with MSVC and run it in a Cygwin shell, it does _not_
> pop up an error dialog box, so presumably it's in the Cygwin runtime,
> specifically the definition of __assert_func.)
>
> --
> William M. (Mike) Miller | Edison Design Group
> william.m.miller@gmail.com

Sorry, should have mentioned running on Win7 Home.

When I try it on my wife's Win10 system, I get the dialog box same as you.

Cheers ... Duncan.