[CMake] Activating coverage with ctest

[ANTON DEGUET]

Hello,

I feel like this is a simple question but I can't figure out the answer.  When 
I try to use ctest -DExperimentalCoverage, I get:

cisst> ctest -D ExperimentalCoverage
   Site: Macintosh.local
   Build name: Darwin-g++-4.0.1--CoVeNuInOs-Py-CNe
Performing coverage
 Cannot find any coverage files.

Is there something specific to add in my DartConfig.cmake?

What I currently have is:
# Options for Dart2
SET(DROP_METHOD "xmlrpc")
SET(DROP_SITE "http://lacuna.cs.jhu.edu:8081")
SET(DROP_LOCATION "cisst")
SET(COMPRESS_SUBMISSION ON)

# the specified NIGHLY_START_TIME. Time is specified in 24 hour format.
SET (NIGHTLY_START_TIME "01:00:00 EDT")

# Coverage
SET(CTEST_COVERAGE_COMMAND ${COVERAGE_COMMAND})


Anton