CMake find_package() cannot find include dirs

Question

I am trying to install two projects: Foo and NeedsFoo. I have successfully compiled and locally installed Foo using cmake. However, I'm on a server and cmake doesn't appear to "remember" where Foo is.

In the cmake to configure NeedsFoo I have

list(APPEND CMAKE_MODULE_PATH "<prefix>/foo-install/CMake/FOO") # add path to FOOConfig.cmake
find_package(FOO REQUIRED)
if( FOO_FOUND )
   MESSAGE(STATUS "Found FOO!")
endif( FOO_FOUND )

MESSAGE(STATUS ${FOO_INCLUDE_DIRS})

"Found Foo!" is printed --- so cmake finds FOO --- but the variable ${FOO_INCLUDE_DIRS} is empty and, therefore, the package does not compile. Any thoughts?

EDIT: There seems to be another copy of Foo installed on the server. Unfortunately, I can't use it (it is the 'master' branch of our project and I need to use my own branch). I tried changing the find_package call to

find_package(FOO REQUIRED PATHS "<prefix>/foo-install/CMake/Foo" NO_DEFAULT_PATH) 

but that did not solve the problem.

Answer 1

Make sure the headers are installed, often you'll need to install a -dev or -devel package to get the headers. If they are installed and you can see them in your system, they might be on a path that cmake isn't expecting. Open the findFoo.cmake file (on Linux this will generally be in /usr/share/c make-xy/modules) and check the list of expected locations, see if you're have installed in a less conventional one.