[CMake] Testing commands that are intended to fail

[John P. Hartmann]

Excuse me for asking a no doubt obvious question.

The test case (objlink is the executable):

add_test( null    objlink )

The log:

Output:
----------------------------------------------------------
Positional argument(s) missing.  0 specified, 1 required.
<end of output>
Test time =   0.01 sec
----------------------------------------------------------
Test Failed.

Test was actually successful.  I'd like to verify that the return value
is 8 and that the above message is issued to standard error.  The test
should fail for any other return value or if anything is written to 
stdout or if anything else is written to stderr.

Howto, please?