We can't test this in the GeneratorExpression unit test because the ';' chars are processed specically by the CMake function argument parser.
This use of generator expressions, like all others to come which operate on target properties, must initalize the dag checker.
Eliminate callers of cmMakefile::GetIncludeDirectories. All callers of GetIncludeDirectories should go through the local generator object. Only the local generator calls cmTarget::GetIncludeDirectories directly.
Stephen Kelly