installing to a custom path

[andrei-pavel]

Hello!

When installing sysrepo from sources, I am able to have libyang installed in a custom path by providing this command:

cmake -DLIBYANG_INCLUDE_DIR="/opt/libyang/include" -DLIBYANG_LIBRARY="/opt/libyang/lib/libyang.so"

This doesn't seem to be an option for libyang-cpp and libsysrepo-cpp. Could this be done?

My goal is to have all four repos installed in custom paths, so that they can be easily uninstalled without make uninstall which requires the user to have access to the sources.

Thanks!

[syyyr]

Hi,

it is possible to install libyang-cpp in a custom path by using the CMAKE_INSTALL_PREFIX variable. So, in your case, your cmake invocation would look something like this:

cmake -DCMAKE_INSTALL_PREFIX="/opt/libyang-cpp"

Let me know, if you have any more questions.

[andrei-pavel]

-- Checking for modules 'libyang>=2.0.7;libyang'
--   Package 'libyang', required by 'virtual:world', not found
--   Package 'libyang', required by 'virtual:world', not found
CMake Error at /usr/share/cmake-3.21/Modules/FindPkgConfig.cmake:562 (message):
A required package was not found

It can't find /opt/libyang.

[syyyr]

This is more of a cmake problem, then libyang/libyang-cpp problem, but if you installed libyang in a non-standard location, you need to tell cmake where libyang is. If you installed libyang with this command:

cmake -DLIBYANG_INCLUDE_DIR="/opt/libyang/include" -DLIBYANG_LIBRARY="/opt/libyang/lib/libyang.so"

then it should be enough to set the CMAKE_PREFIX_PATH variable to /opt/libyang when invoking cmake for libyang-cpp. We are using pkg-config to find libyang.

[andrei-pavel]

That's the problem I'm facing. Those commands don't work. Taking inspiration from sysrepo, I think libyang-cpp needs these lines in CMakeLists.txt:

target_link_libraries(libyang-cpp ${LIBYANG_LIBRARIES})
include_directories(${LIBYANG_INCLUDE_DIRS})

[syyyr]

libyang is linked to libyang-cpp through pkg-config. That means that as long as pkg-config knows where libyang is, then libyang-cpp will also know where it is. So it all comes down to whether it does know, or does not. One way to debug pkg-config is to use this command:

pkg-config libyang --libs

If this gives an error, you need to tell pkg-config where libyang is. There are two options.

1. point the PKG_CONFIG_PATH enviromental variable to your libyang prefix when invoking cmake
2. if your cmake is new enough (version 3.1), set the CMAKE_PREFIX_PATH to the install prefix of libyang and cmake should append this path to PKG_CONFIG_PATH automatically.

[andrei-pavel]

Thanks much!