CMake Error at BadIF.cmake:2 \(add_custom_target\): Error evaluating generator expression: \$<IF:asdf,a,b> First parameter to \$<IF> must resolve to exactly one '0' or '1' value. Call Stack \(most recent call first\): CMakeLists.txt:3 \(include\) + CMake Error at BadIF.cmake:2 \(add_custom_target\): Error evaluating generator expression: \$<IF:asdf,a> \$<IF> expression requires 3 comma separated parameters, but got 2 instead.