project(ANOTHER_PROJ) # subdir to an out of source and out of binary directory add_subdirectory(${OutOfSource_SOURCE_DIR}/../OutOfBinary ${OutOfSource_BINARY_DIR}/../OutOfBinary) # subdir to a sibling dir add_subdirectory(${OutOfSource_SOURCE_DIR}/${KEN}OutOfSourceSubdir OutOfSourceSubdir ) add_library(subdir subdir.c)