https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100164
--- Comment #15 from Thomas Rodgers <rodgertq at gcc dot gnu.org> --- >From the most recent patch - + _GLIBCXX_ALWAYS_INLINE bool + _M_try_acquire() noexcept + { + for (;;) + { + auto __err = sem_trywait(&_M_semaphore); + if (__err && (errno == EINTR)) + continue; + else if (__err && (errno == EAGAIN)) + return false; + else if (__err) + std::terminate(); + else + break; + } + return true; + } + You are correct it was never exercised. I saw then when I forced it in the test case and then added the above. I don't understand why you are seeing this error if you've applied the 0001-libstdc-Work-around-for-PR100164 patch. I don't see it locally.