Setting CMAKE_INSTALL_PREFIX from CMakeLists.txt file

Question

How do I set CMAKE_INSTALL_PREFIX in my root CMakeLists.txt file?

I have been doing

cmake_minimum_required(VERSION 2.8)
project(MyProject)

# Set def         


        

Answer 1

CMake developers suggest to use given pattern for change default value of CMAKE_INSTALL_PREFIX inside CMakeLists.txt:

# Use this snippet *after* PROJECT(xxx):
IF(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
  SET(CMAKE_INSTALL_PREFIX <path> CACHE PATH <comment> FORCE)
ENDIF(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)

---

Using that approach

# Use this snippet *before* PROJECT(xxx):
SET(CMAKE_INSTALL_PREFIX <path> CACHE PATH <comment>)

is not recommended:

.. solution depends on the implementation details of the PROJECT command and is very fragile since it works "accidentally" for some versions of CMake. I don't consider it to be an option at all.