CMake version recommendations and install

CMake ≥ 3.21 is strongly recommended for general users for more robust and easy syntax. For project developers, we recommend CMake ≥ 3.28 for C++20 modules and IDE integration.

Downloading the latest release of CMake is usually easy. Admin / sudo is NOT required.

For platforms where CMake binaries aren’t easily available, use scripts/build_cmake.cmake.

To see the merge requests for a certain release, use a URL like: https://gitlab.kitware.com/cmake/cmake/-/merge_requests?milestone_title=3.28.4&scope=all&state=all

CMake 3.29 adds cmake_language(EXIT code) to exit CMake script mode with a specific return code. This is useful when using CMake as a platform-agnostic scripting language instead of shell script. Environment variable CMAKE_INSTALL_PREFIX is used to set the default install prefix across projects–it can be overridden as typical by cmake -DCMAKE_INSTALL_PREFIX= option. Target property TEST_LAUNCHER allows specifying a test launcher e.g. for MPI program this allows deduplicating or making more programmatic test runner scripts. Linker information variables including CMAKE__COMPILER_LINKER_ID have been added to allow programmatic logic like setting target_link_options() based on the particular linker. ctest --parallel without a number or 0 will use unbounded test run parallelism.

CMake 3.28 changes PATH behavior for Windows find_{library,path,file}() to no longer search PATH. This may break some projects that rely on PATH for finding libraries. The MSYS2-distributed CMake is patched to include PATH like earlier CMake, which can be confusing for CI etc. not using MSYS CMake with that patch. Windows CI/user may need to specify environment variable CMAKE_PREFIX_PATH like

$Env:SYSTEMDRIVE/msys64/mingw64/lib

Support for C++20 modules is considerably improved and most users will want at least CMake 3.28 to make C++ modules usable. Generator expressions $<IF> $<AND> $<OR> now short circuit. Test properties now have a DIRECTORY parameter, useful for setting test parameters from the project’s top level CMakeLists.txt. CMake 3.28.4 fixed a long-standing bug in Ninja Fortran targets that use include statements.

CMake 3.27 emits warning for cmake_minimum_required(VERSION) < 3.5. CTest test properties TIMEOUT_SIGNAL_NAME and TIMEOUT_SIGNAL_GRACE_PERIOD specify a POSIX signal to send to a timed out test process. Interactive CMake debugger added by cmake --debugger is used with an IDE such as Visual Studio. CMake script command cmake_file_api() allows querying CMake File API from within CMake. NOTE: Fortran + Ninja was broken for OBJECT libraries in CMake 3.27.0..3.27.8 and fixed in 3.27.9.

Older CMake changelog