incorrect value for `target_link_libraries`

[haampie]

In

cprnc/CMakeLists.txt

Lines 86 to 87 in fec7c42

	target_link_libraries (cprnc
	PUBLIC ${NetCDF_Fortran_LIBRARIES} ${NetCDF_C_LIBRARIES} ${NetCDF_LIBRARIES})

The NetCDF_*LIBRARIES variables are strings of linker flags -L<path> -l<lib>.

But target_link_libraries expects full paths to libraries like <path>/lib<lib>.so, otherwise CMake does not know what libraries are effectively being linked.

So even though the build works fine, features like CMAKE_INSTALL_RPATH_USE_LINK_PATH=ON do not work, because <path> is not among the known link directories.

Instead of using nc-config --libs, you could use pkg-config, for which CMake has builtin support:

https://cmake.org/cmake/help/latest/module/FindPkgConfig.html

In particular pkg_search_module would then give you *_LIBRARIES which is a list of full paths, which can be used in target_link_libraries, so that CMAKE_INSTALL_RPATH_USE_LINK_PATH=ON works again.

[climbfuji]

The "correct" way (simply because it is the widely accepted standard across the NWP community) to find and link to netCDF is by (a) updating findNetcdf.cmake to this version https://github.com/NOAA-EMC/CMakeModules/blob/develop/Modules/FindNetCDF.cmake or the ECMWF one (these two versions are nearly the same, and functionally identical). Then, one can simply do (example from Unified Forecast System/CCPP):

find_package(NetCDF 4.7.4 REQUIRED C Fortran)
...
target_link_libraries(myproject PUBLIC NetCDF::NetCDF_Fortran NetCDF::NetCDF_C)

and that takes care of the include and linker flags. And, as an aside, this works with spack.

[rljacob]

@climbfuji see changes implemented in #19

[haampie]

Closed by #19