| CPACK_SET_DESTDIR | |
| ----------------- | |
| Boolean toggle to make CPack use ``DESTDIR`` mechanism when packaging. | |
| ``DESTDIR`` means DESTination DIRectory. It is commonly used by makefile | |
| users in order to install software at non-default location. It is a | |
| basic relocation mechanism that should not be used on Windows (see | |
| :variable:`CMAKE_INSTALL_PREFIX` documentation). It is usually invoked like | |
| this: | |
| .. code-block:: sh | |
| make DESTDIR=/home/john install | |
| which will install the concerned software using the installation | |
| prefix, e.g. ``/usr/local`` prepended with the ``DESTDIR`` value which | |
| finally gives ``/home/john/usr/local``. When preparing a package, CPack | |
| first installs the items to be packaged in a local (to the build tree) | |
| directory by using the same ``DESTDIR`` mechanism. Nevertheless, if | |
| ``CPACK_SET_DESTDIR`` is set then CPack will set ``DESTDIR`` before doing the | |
| local install. The most noticeable difference is that without | |
| ``CPACK_SET_DESTDIR``, CPack uses :variable:`CPACK_PACKAGING_INSTALL_PREFIX` | |
| as a prefix whereas with ``CPACK_SET_DESTDIR`` set, CPack will use | |
| :variable:`CMAKE_INSTALL_PREFIX` as a prefix. | |
| Manually setting ``CPACK_SET_DESTDIR`` may help (or simply be necessary) | |
| if some install rules uses absolute ``DESTINATION`` (see CMake | |
| :command:`install` command). However, starting with CPack/CMake 2.8.3 RPM | |
| and DEB installers tries to handle ``DESTDIR`` automatically so that it is | |
| seldom necessary for the user to set it. |