c4275592a8
The FindPackageHandleStandardArgs module was originally created outside of CMake. It was added for CMake 2.6.0 by commit e118a627 (add a macro FIND_PACKAGE_HANDLE_STANDARD_ARGS..., 2007-07-18). However, it also proliferated into a number of other projects that at the time required only CMake 2.4 and thus could not depend on CMake to provide the module. CMake's own find modules started using the module in commit b5f656e0 (use the new FIND_PACKAGE_HANDLE_STANDARD_ARGS in some of the FindXXX modules..., 2007-07-18). Then commit d358cf5c (add 2nd, more powerful mode to find_package_handle_standard_args, 2010-07-29) added a new feature to the interface of the module that was fully optional and backward compatible with all existing users of the module. Later commit 5f183caa (FindZLIB: use the FPHSA version mode, 2010-08-04) and others shortly thereafter started using the new interface in CMake's own find modules. This change was also backward compatible because it was only an implementation detail within each module. Unforutnately these changes introduced a problem for projects that still have an old copy of FindPackageHandleStandardArgs in CMAKE_MODULE_PATH. When any such project uses one of CMake's builtin find modules the line include(FindPackageHandleStandardArgs) loads the copy from the project which does not have the new interface! Then the including find module tries to use the new interface with the old module and fails. Whether this breakage can be considered a backward incompatible change in CMake is debatable. The situation is analagous to copying a standard library header from one version of a compiler into a project and then observing problems when the next version of the compiler reports errors in its other headers that depend on its new version of the original header. Nevertheless it is a change to CMake that causes problems for projects that worked with previous versions. This problem was discovered during the 2.8.3 release candidate cycle. It is an instance of a more general problem with projects that provide their own versions of CMake modules when other CMake modules depend on them. At the time we resolved this instance of the problem with commit b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake everywhere, 2010-09-28) for the 2.8.3 release. In order to address the more general problem we introduced policy CMP0017 in commit db44848f (Prefer files from CMAKE_ROOT when including from CMAKE_ROOT, 2010-11-17). That change was followed by commit ce28737c (Remove usage of CMAKE_CURRENT_LIST_DIR now that we have CMP0017, 2010-12-20) which reverted the original workaround in favor of using the policy. However, existing project releases do not set the policy behavior to NEW and therefore still exhibit the problem. We introduced in commit a364daf1 (Allow users to specify defaults for unset policies, 2011-01-03) an option for users to build existing projects by adding -DCMAKE_POLICY_DEFAULT_CMP0017=NEW to the command line. Unfortunately this solution still does not allow such projects to build out of the box, and there is no good way to suggest the use of the new option. The only remaining solution to keep existing projects that exhibit this problem building is to restore the change originally made in commit b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake everywhere, 2010-09-28). This also avoids policy CMP0017 warnings for this particular instance of the problem the policy addresses.
This is CMake, the cross-platform, open-source make system. CMake is distributed under the BSD License, see Copyright.txt. For documentation see the Docs/ directory once you have built CMake or visit http://www.cmake.org. Building CMake ============== Supported Platforms ------------------- MS Windows, Mac OS X, Linux, FreeBSD, Solaris, HP-UX, IRIX, BeOS, QNX Other UNIX-like operating systems may work too out of the box, if not it shouldn't be a major problem to port CMake to this platform. Contact the CMake mailing list in this case: http://www.cmake.org/mailman/listinfo/cmake If you don't have any previous version of CMake already installed -------------------------------------------------------------- * UNIX/Mac OSX/MinGW/MSYS/Cygwin: You need to have a compiler and a make installed. Run the bootstrap script you find the in the source directory of CMake. You can use the --help option to see the supported options. You may want to use the --prefix=<install_prefix> option to specify a custom installation directory for CMake. You can run the bootstrap script from within the CMake source directory or any other build directory of your choice. Once this has finished successfully, run make and make install. So basically it's the same as you may be used to from autotools-based projects: $ ./bootstrap; make; make install * Other Windows: You need to download and install a binary release of CMake in order to build CMake. You can get these releases from http://www.cmake.org/HTML/Download.html . Then proceed with the instructions below. You already have a version of CMake installed --------------------------------------------- You can build CMake as any other project with a CMake-based build system: run the installed CMake on the sources of this CMake with your preferred options and generators. Then build it and install it. For instructions how to do this, see http://www.cmake.org/HTML/RunningCMake.html