CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_EXPORT_NO_PACKAGE_REGISTRY


CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_EXPORT_NO_PACKAGE_REGISTRY
    CMAKE_INSTALL_BINDIR
    CMAKE_INSTALL_DATAROOTDIR
    CMAKE_INSTALL_INCLUDEDIR
    CMAKE_INSTALL_LIBDIR
    CMAKE_INSTALL_LIBEXECDIR
    CMAKE_INSTALL_OLDINCLUDEDIR
    CMAKE_INSTALL_SBINDIR


/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:20:31: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
constexpr Person_PhoneNumber::Person_PhoneNumber(
                              ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:20:31: note: non-literal type '::google::protobuf::Message' cannot be used in a constant expression
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:26:13: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
  constexpr Person_PhoneNumberDefaultTypeInternal()
            ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:27:7: note: non-literal type 'tutorial::Person_PhoneNumber' cannot be used in a constant expression
    : _instance(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized{}) {}
      ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:34:19: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
constexpr Person::Person(
                  ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:34:19: note: non-literal type '::google::protobuf::Message' cannot be used in a constant expression
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:42:13: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
  constexpr PersonDefaultTypeInternal()
            ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:43:7: note: non-literal type 'tutorial::Person' cannot be used in a constant expression
    : _instance(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized{}) {}
      ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:50:24: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
constexpr AddressBook::AddressBook(
                       ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:50:24: note: non-literal type '::google::protobuf::Message' cannot be used in a constant expression
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:54:13: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
  constexpr AddressBookDefaultTypeInternal()
            ^
/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813/addressbook.pb.cc:55:7: note: non-literal type 'tutorial::AddressBook' cannot be used in a constant expression
    : _instance(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized{}) {}
      ^
6 errors generated.
make[2]: *** [CMakeFiles/test_package.dir/addressbook.pb.cc.o] Error 1
make[1]: *** [CMakeFiles/test_package.dir/all] Error 2
make: *** [all] Error 2
[HOOK - conan-center.py] post_package_info(): WARN: [LIBRARY DOES NOT EXIST (KB-H054)] Component protobuf::protobuf libdir "lib" does not contain any declared library
ERROR: protobuf/3.15.4 (test package): Error in build() method, line 14
	cmake.build()
	ConanException: Error 2 while executing cmake --build '/home/conan/w/cci_PR-4776/10/3500fc4e-773b-4f6b-9ae2-d2fe1ada87fa/recipes/protobuf/all/test_package/build/969674adec09b99380eb7c89d7fda5cac719f813' '--' '-j3'