Unresolved symbols during build

[nrath-js]

I'm building with

          "-DUSE_THIRDPARTY_LIBRARIES=OFF"
          "-DENABLE_TESTING=OFF"
          "-DENABLE_PUSH=OFF"
          "-DTHIRDPARTY_CIVETWEB_WITH_SSL=OFF"
          "-DBUILD_SHARED_LIBS=OFF"

..but when I'm eventually linking the static libprometheus-cpp-static into my program, I'm getting a number of warnings about unresolved symbols:

/nix/store/fmc9d0xbcgfcwg8fyw9w9908wca58y9k-x86_64-unknown-linux-musl-binutils-2.41/bin/x86_64-unknown-linux-musl-ld: /nix/store/if5gxjzaxk1mhnvs48w5k0n45wz4ryfb-prometheus-cpp-static-x86_64-unknown-linux-musl-1.1.0/lib/libprometheus-cpp-pull.a(exposer.cc.o): in function `prometheus::Exposer::Exposer(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, CivetCallbacks const*)':
(.text+0x2c): undefined reference to `CivetServer::CivetServer(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, CivetCallbacks const*, void const*)'
/nix/store/fmc9d0xbcgfcwg8fyw9w9908wca58y9k-x86_64-unknown-linux-musl-binutils-2.41/bin/x86_64-unknown-linux-musl-ld: /nix/store/if5gxjzaxk1mhnvs48w5k0n45wz4ryfb-prometheus-cpp-static-x86_64-unknown-linux-musl-1.1.0/lib/libprometheus-cpp-pull.a(exposer.cc.o): in function `prometheus::Exposer::GetListeningPorts() const':
(.text+0x85c): undefined reference to `CivetServer::getListeningPorts()'
/nix/store/fmc9d0xbcgfcwg8fyw9w9908wca58y9k-x86_64-unknown-linux-musl-binutils-2.41/bin/x86_64-unknown-linux-musl-ld: /nix/store/if5gxjzaxk1mhnvs48w5k0n45wz4ryfb-prometheus-cpp-static-x86_64-unknown-linux-musl-1.1.0/lib/libprometheus-cpp-pull.a(endpoint.cc.o): in function `prometheus::detail::Endpoint::RegisterAuth(std::function<bool (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&)>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
(.text+0x14c): undefined reference to `CivetServer::addAuthHandler(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, CivetAuthHandler*)'
[....]

Am I doing something wrong, or is this configuration not supported? If it's not supported, shouldn't CMake error out instead of producing a static library with missing symbols?