Use boost from Git repo together with CMake External Project

CMakeLists.txt

project(regex)

cmake_minimum_required(VERSION 2.8)

# For some external project macros
include(ExternalProject)

# Download boost from git and build regex module

ExternalProject_Add(
    boost
    PREFIX ${CMAKE_CURRENT_BINARY_DIR}/boost
    GIT_REPOSITORY https://github.com/ryppl/boost-svn.git
    GIT_TAG "Boost_1_41_0"
    CONFIGURE_COMMAND ""
    BUILD_COMMAND bjam --with-regex toolset=gcc variant=debug link=static install --prefix=${CMAKE_CURRENT_BINARY_DIR}/boostinstall
    BUILD_IN_SOURCE 1
    INSTALL_COMMAND ""
)

set(Boost_INCLUDE_DIRS ${CMAKE_CURRENT_BINARY_DIR}/boostinstall/include)
set(Boost_LIBRARIES ${CMAKE_CURRENT_BINARY_DIR}/boostinstall/lib/libboost_regex.a)

# Configure app

include_directories(${Boost_INCLUDE_DIRS})
add_executable(regex regex.cpp)
add_dependencies(regex boost)
target_link_libraries(regex ${Boost_LIBRARIES})

regex.cpp

#include "boost/regex.hpp"
#include "boost/version.hpp"
#include <iostream>
int main(int argc, char **argv) {	
	static const std::string regex("YOUR_REGEX");
	static const std::string str("foo");
	std::cerr << std::endl << "Boost Version = " << BOOST_VERSION << std::endl;
	std::cerr << std::endl << "Regex = " << regex << std::endl;
	std::cerr << std::endl << "Search string = " << str << std::endl << std::endl;
	try {
		static const boost::regex e(regex);
		std::cerr << "Match result = " << boost::regex_match("foo", e ) << std::endl;
	} catch (boost::regex_error const & ex) {
		std::cerr << "exception = " << ex.what() << std::endl;
	} catch (...) {
		std::cerr << "unknown exception" << std::endl;
	}
	return 0;
}

this is a flipping awesome example!!!