Exclude the values of the CMAKE_INSTALL_PREFIX and CMAKE_STAGING_PREFIX variables from CMAKE_SYSTEM_PREFIX_PATH. CMake adds these project-destination prefixes to CMAKE_SYSTEM_PREFIX_PATH by default in order to support building a series of dependent packages and installing them into a common prefix. Set CMAKE_FIND_NO_INSTALL_PREFIX to TRUE to suppress this behavior.

The CMAKE_SYSTEM_PREFIX_PATH is initialized on the first call to a project() or enable_language() command. Therefore one must set CMAKE_FIND_NO_INSTALL_PREFIX before this in order to take effect. A user may set the variable as a cache entry on the command line to achieve this.

Note that the prefix(es) may still be searched for other reasons, such as being the same prefix as the CMake installation, or for being a built-in system prefix.