cmake_minimum_required(VERSION 2.8 FATAL_ERROR) macro( MACRO_ENSURE_OUT_OF_SOURCE_BUILD _errorMessage ) string( COMPARE EQUAL "${CMAKE_SOURCE_DIR}" "${CMAKE_BINARY_DIR}" _insource ) if( _insource ) message( SEND_ERROR "${_errorMessage}" ) message( FATAL_ERROR "In-source builds are not allowed. This process created the file `CMakeCache.txt' and the directory `CMakeFiles and overwrite the Makefile. Please fix them with: rm -r CMakeCache.txt CMakeFiles git checkout Makefile CMake would overwrite the makefiles distributed with Compiler-RT. Please create a directory outside the source directory and run cmake from there, passing the path to this source directory as the last argument. Example for the lazy people: mkdir ../PacketLib_build cd ../PacketLib_build cmake ../PacketLib " ) endif( _insource ) endmacro( MACRO_ENSURE_OUT_OF_SOURCE_BUILD ) set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/CMakeModules) MACRO_ENSURE_OUT_OF_SOURCE_BUILD( "In-source build error." ) project(packet) set(packet_MAJOR_VERSION 4) set(packet_MINOR_VERSION 5) set(packet_PATCH_VERSION 0) set(packet_VERSION ${packet_MAJOR_VERSION}.${packet_MINOR_VERSION}.${packet_PATCH_VERSION}) set(PROJECT_VERSION ${packet_VERSION}) add_subdirectory(src)