Tests/RunCMake/GeneratorExpression/BadCONFIG.cmake - third_party/github.com/Kitware/CMake - Git at Google

 add_custom_target(check ALL COMMAND check
   $<CONFIG:.>
   $<CONFIG:Foo-Bar>
   $<$<CONFIG:Foo-Nested>:foo>
   VERBATIM)
	add_custom_target(check ALL COMMAND check
	$<CONFIG:.>
	$<CONFIG:Foo-Bar>
	$<$<CONFIG:Foo-Nested>:foo>
	VERBATIM)