[CMake] ctest ques.: capture driver errs

[Dean Inglis]

I have a build similar to VTK/Examples/Build/vtkMy
and I have added ctest funtionality to test my custom
VTK classes.  In a test driver that evaluates numeric
expressions, e.g.  a stupid ex.:

in myTest(int,char*[])
{
  int a =1;
  int b = 2;
  int retVal = 0;
  if((a + b) != 500)
    {
    vtkGenericWarningMacro(<<"err: a + b != 500, a = " << a<<", b = " << b);
    retVal = 1;
    }
  return retVal;
}

I want to retrieve some form of diagnostic message either at console
or to a log file.  Is there a way to do this with cmake/ctest or do
I have to explicitly write out my error diagnostics to a file?
Replacing vtkGenericWarningMacro( with cout does not pipe output
to the console: ctest prevents this.

Dean