nathan@nathan-lenovo:~/Projects/brlcad-svn-trunk$ make clean
nathan@nathan-lenovo:~/Projects/brlcad-svn-trunk$ cmake -DBRLCAD_ENABLE_TK=ON -DBRLCAD_TK=SYSTEM
**********************************************************
*** Configuring BRL-CAD Release 7.25.0, Build 20150126 ***
**********************************************************
CMake Error at CMakeLists.txt:487 (_message):
  Local Tcl compilation enabled, but compilation of Tcl/Tk extension Tk has
  been disabled - unsupported configuration!
Call Stack (most recent call first):
  misc/CMake/ThirdParty_TCL.cmake:219 (message)
  src/other/CMakeLists.txt:403 (THIRD_PARTY_TCL_PACKAGE)


-- Configuring incomplete, errors occurred!
See also "/home/nathan/Projects/brlcad-svn-trunk/CMakeFiles/CMakeOutput.log".
See also "/home/nathan/Projects/brlcad-svn-trunk/CMakeFiles/CMakeError.log".
nathan@nathan-lenovo:~/Projects/brlcad-svn-trunk$