Out of source build error

[pamely]

I am currently trying the "Compiling a YARP hello world program" available on the following link . After running cmake to build the package hello, I got the error below:

CMake Error at CMakeLists.txt:16 (find_package):
  By not providing "FindYARP.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "YARP", but
  CMake did not find one.

  Could not find a package configuration file provided by "YARP" with any of
  the following names:

    YARPConfig.cmake
    yarp-config.cmake

  Add the installation prefix of "YARP" to CMAKE_PREFIX_PATH or set
  "YARP_DIR" to a directory containing one of the above files.  If "YARP"
  provides a separate development package or SDK, be sure it has been
  installed.

While I understand that I have to prepend "YARP" to CMAKE_PREFIX_PATH, I don't know how to find the path to YARP installation prefix.
Please, how can I fix this?

As suggested in the tutorial, I have the following directory structure:
/yarp/hello/CMakeLists.txt
/yarp/hello/hello.cpp
/yarp/hello/build

I am running cmake .. in the build folder.

Thank you,
Pamely

[pattacini]

How did you build YARP?

⬜ Just build w/o install

If you didn't install it (you just typed make), then you ought to follow one of the proposed suggestions:

  Add the installation prefix of "YARP" to CMAKE_PREFIX_PATH or set
  "YARP_DIR" to a directory containing one of the above files.  If "YARP"
  provides a separate development package or SDK, be sure it has been
  installed.

⚪ Suggestion 1 (CMAKE_PREFIX_PATH)

cd /yarp/hello/build
cmake -DCMAKE_PREFIX_PATH=/path_to_yarp_build_dir ..

where /path_to_yarp_build_dir shall point to the directory where you built YARP.

Alternatively, you could export CMAKE_PREFIX_PATH as an env variable.

⚪ Suggestion 2 (YARP_DIR)

Put the line below into your .bashrc file

export YARP_DIR=/path_to_yarp_build_dir

⬜ Build and install

By contrast, if you installed YARP by typing make install, just have a look at where the compilation products have been installed by inspecting the build log or checking the value of the CMAKE_INSTALL_PREFIX cmake variable.

Usually, CMAKE_INSTALL_PREFIX points to /usr/local/ so that you should be able to let cmake find what's needed w/o fiddling any further.

If CMAKE_INSTALL_PREFIX points to a user-defined directory, then one needs to fill in other env variables like PATH, LD_LIBRARY_PATH, YARP_DATA_DIRS with the correct paths.