undefined reference to jwtpp::claims::claims()

[NeleOb]

Hi troian,
I have the following problem:
When inserting the following line into my code:

jwtpp::claims cl;

I get the following error code when building:

undefined reference to `jwtpp::claims::claims()`

The same with:

std::string key = "some";
std::string value = "test";
cl.set().any(key, value);
undefined reference to `jwtpp::claims::set::any(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'

and

std::string encoded = jws::sign_bearer(cl, signer);
undefined reference to `jwtpp::jws::sign_bearer[abi:cxx11](jwtpp::claims&, std::shared_ptr<jwtpp::crypto>)'

and

jwtpp::sp_jws jws = jws::parse(encoded);
undefined reference to `jwtpp::jws::parse(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'

On the other hand the following lines work:

cl.set().nbf(value);
cl.set().exp(value);
jwtpp::sp_crypto signer = std::make_shared<jwtpp::hmac>("secret", jwtpp::alg_t::HS256);

I used the tests as a guide and examples.

Could you please help me?

CMakeLists.txt:

cmake_minimum_required(VERSION 3.0.0)
project(project VERSION 0.1.0)

include(CTest)
enable_testing()

find_package(OpenSSL REQUIRED)

# C++ Library 
add_subdirectory(jsoncpp)
get_target_property(jsoncpp/include jsoncpp_lib INTERFACE_INCLUDE_DIRECTORIES)
include_directories(jsoncpp/include)
add_library(jwtpp INTERFACE)
target_include_directories(jwtpp INTERFACE jwtpp/include)

add_executable(project main.cpp libraries_cpp_jwtpp_2.cpp)

target_link_libraries(project jwtpp jsoncpp_lib)

set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
include(CPack)

[troian]

undefined reference usually means it cannot link the the source.

mind sharing entire project somehow?