No cmake modules installed

[Paul Bovbel]

Upstream (https://github.com/nlohmann/json/tree/develop/cmake) provides modules to use find_package to import into a CMake project.

The project install this file here (https://github.com/nlohmann/json/blob/develop/CMakeLists.txt#L155), but it is not included in the deb package.

[Hans Joachim Desserud (hjd)]

Thanks for reporting.

I noticed that the package does contain some cmake files, though I am not sure if that means they are incomplete or if cmake fails to find them:

/usr/lib/cmake/nlohmann_json/nlohmann_jsonConfig.cmake
/usr/lib/cmake/nlohmann_json/nlohmann_jsonConfigVersion.cmake
/usr/lib/cmake/nlohmann_json/nlohmann_jsonTargets.cmake
(https://packages.ubuntu.com/focal/all/nlohmann-json3-dev/filelist)

Btw, when reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. This will automatically add additional information like version numbers and Ubuntu release. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Gianfranco Costamagna (costamagnagianfranco)]

cat array.cpp
#include <iostream>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main()
{
    // create JSON arrays
    json j_no_init_list = json::array();
    json j_empty_init_list = json::array({});
    json j_nonempty_init_list = json::array({1, 2, 3, 4});
    json j_list_of_pairs = json::array({ {"one", 1}, {"two", 2} });

    // serialize the JSON arrays
    std::cout << j_no_init_list << '\n';
    std::cout << j_empty_init_list << '\n';
    std::cout << j_nonempty_init_list << '\n';
    std::cout << j_list_of_pairs << '\n';
}

cat CMakeLists.txt
project(foo)
cmake_minimum_required(VERSION 3.0)
find_package(nlohmann_json)
add_executable(array main.cpp)

cmake .

-- The C compiler identification is GNU 9.3.0
-- The CXX compiler identification is GNU 9.3.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found nlohmann_json: /usr/lib/cmake/nlohmann_json/nlohmann_jsonConfig.cmake (found version "3.10.2")
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/nlohmann

make
[ 50%] Building CXX object CMakeFiles/array.dir/main.cpp.o
[100%] Linking CXX executable array
[100%] Built target array

[Launchpad Janitor (janitor)]

[Expired for nlohmann-json3 (Ubuntu) because there has been no activity for 60 days.]