https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89464
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- The problem is in https://github.com/Silicondust/libhdhomerun: hdhomerun_os_posix.h Which does: #if !defined(alignas) #define alignas(n) __attribute__((aligned(n))) #endif That is wrong.