attribute appertains to a friend declaration that is not a definition

boost/thread/detail/thread.hpp の641行目から始め、main.cpp から Kodierungstheorie ターゲットをビルドする、報告された CMake ビルドを再現してください。診断に関係するコンパイラーと Boost の構成を確認してください。friend-declaration 属性エラーなしでターゲットがビルドできれば完了です。

====================[ Build | Kodierungstheorie | Debug ]=======================
/usr/local/bin/cmake --build /home/benjamin-elias/CLionProjects/Kodierungstheorie/cmake-build-debug --target Kodierungstheorie -- -j 6
Scanning dependencies of target Kodierungstheorie
[ 16%] Building CXX object CMakeFiles/Kodierungstheorie.dir/main.cpp.o
In Datei, eingebunden von /home/benjamin-elias/Downloads/boost_1_76_0/boost/thread/thread_only.hpp:22,
von /home/benjamin-elias/Downloads/boost_1_76_0/boost/thread/thread.hpp:12,
von /home/benjamin-elias/Downloads/boost_1_76_0/boost/thread.hpp:13,
von /home/benjamin-elias/CLionProjects/Kodierungstheorie/main.cpp:2:
/home/benjamin-elias/Downloads/boost_1_76_0/boost/thread/detail/thread.hpp:641:37: Fehler: attribute appertains to a friend declaration that is not a definition
641 | friend id BOOST_THREAD_DECL this_thread::get_id() BOOST_NOEXCEPT;
| ^~~~~~~~~~~
make[3]: *** [CMakeFiles/Kodierungstheorie.dir/build.make:72: CMakeFiles/Kodierungstheorie.dir/main.cpp.o] Fehler 1
make[2]: *** [CMakeFiles/Makefile2:85: CMakeFiles/Kodierungstheorie.dir/all] Fehler 2
make[1]: *** [CMakeFiles/Makefile2:92: CMakeFiles/Kodierungstheorie.dir/rule] Fehler 2
make: *** [Makefile:124: Kodierungstheorie] Fehler 2