https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64919
--- Comment #13 from Joseph John <josephpattara at gmail dot com> --- Yes. i also tried without the mlp64 option both for building the 4.7.4 and also for building the 4.9.2 using the 4.7.4 but again I have the same issue. Means. * 4.7.4 build is successful. * 4.9.2 build fails at libstdc++-v3 as below. /home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include/type_traits:471:60: error: template argument 1 is invalid /home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include/type_traits:479:62: error: template argument 1 is invalid /home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include/type_traits:483:63: error: template argument 1 is invalid In file included from /home/jjohn/hpux/gcc_492/gcc-4.9.2/libstdc++-v3/include/precompiled/stdc++.h:103:0: /home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include/future:1509:5: error: looser throw specifier for 'virtual std::__future_base::_Async_state_commonV2::~_Async_state_commonV2()' /home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include/future:316:15: error: overriding 'virtual std::__future_base::_State_baseV2::~_State_baseV2() noexcept (true)' In file included from /home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include/regex:57:0, from /home/jjohn/hpux/gcc_492/gcc-4.9.2/libstdc++-v3/include/precompiled/stdc++.h:108: /home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include/bits/regex_automaton.h:159:24: error: 'std::__detail::_NFA_base::_NFA_base' names constructor Makefile:1596: recipe for target 'ia64-hp-hpux11.31/bits/stdc++.h.gch/O2ggnu++0x.gch' failed make[5]: *** [ia64-hp-hpux11.31/bits/stdc++.h.gch/O2ggnu++0x.gch] Error 1 make[5]: Leaving directory '/home/jjohn/hpux/gcc_492/gcc_build/ia64-hp-hpux11.31/libstdc++-v3/include' The reason I went with using the mpl64 option was with out that option when I was doing a 4.9.2 building using the GCC 4.2.3 which was available by default I was getting the linker issue which is specified in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61577. The only way I got get pass the linker errro just after the libbackend.a creation was using the -mlp64 option for 4.9.2 build. Were you successful in making the 4.9.2 build?