According to https://www.boost.org/users/history/version_1_68_0.html it seems 1.68 has some fixes for context & coroutine2:
Context: #78: Linker error with context-impl=ucontext: multiple definition of boost::context::detail::current_rec Coroutine2: #14: crash while stack unwinding #20: failes to compile test in due to the error C2039 (looks similar with what I enounter on linux) [...] IMHO Debian buster should use 1.68 ... Cheers, BogDan.