How can I get CMake to find my alternative Boost installation?
I have installed the most recent version of Boost in /usr/local (with includes in /usr/local/include/boost and libraries in /usr/local/lib/boost) and I am now attempting to install Wt from source, but CMake (version 2.6) can't seem to find the Boost installation. It tries to give helpful suggestions about setting BOOST_DIR and Boost_LIBRARYDIR, but I haven't been able to get it to work by tweaking these variables.
The most recent error message that I get is that it can't find the libraries, but it seems to indicate that it is using "/usr/local/include" for the include path, which isn't correct (and I can't seem to fix it). Is there a solution for this off the top of their head, or do I need to go mucking around inside CMake to figure it out?
Answer
You should have a look at FindBoost.cmake script, which handles Boost detection and setting up all Boost variables. It typically resides in /usr/share/cmake-2.6/Modules/. In it, you will find documentation. For instance:
# These last three variables are available also as environment variables:
#
# BOOST_ROOT or BOOSTROOT The preferred installation prefix for searching for
# Boost. Set this if the module has problems finding
# the proper Boost installation.
#
In contrast to BOOST_ROOT, the variables you are referring to are actually variables that are set by the FindBoost module. Note that you don't have to (and probably also don't want to) edit your CMake project configuration to set BOOST_ROOT. Instead, you should use the environment variable, e.g. calling
# BOOST_ROOT=/usr/local/... ccmake .