Removing `COMPILER_MODULE_NAME` does not work.  When building anything with ClangGCC (for example, `hwloc-1.6.2-ClangGCC-1.1.2.eb`) I get:

    EasyBuildError: "EasyBuild crashed with an error (at easybuild/eb-install/lib/python2.6/site-packages/easybuild_framework-1.4.0dev-py2.6.egg/easybuild/tools/toolchain/toolchain.py:314 in prepare): List of toolchain dependency modules and toolchain definition do not match (set(['GCC', 'Clang']) vs set(['GCC']))"