[CMake] test executable failing only when run in ctest

[Brad King]

Matthew Leotta wrote:
> I've come across a test on the VXL dashboard that seems to segfault only
> on some test machines.
> 
> http://www.cdash.org/CDash/testSummary.php?project=12&name=bvxm_test_apm_processors&date=2009-01-26
> 
> 
> One of the failing machines is mine (Mac_OS_X-10.5.6_unix_make).  When I
> run the same test executable from the command line, all the tests pass
> and there is no segfault.  Strangely, the segfault only occurs when the
> executable is run by ctest.  I can reproduce the dashboard results by
> running ctest in the executable's directory.  Has anyone seen anything
> like this before?  Any suggestions on how to debug this?

Hack the test command line to run gdb on the test executable.  Then run
the test inside it by hand.

-Brad