We are porting GCC releases/gcc-10.1.0. The following error is seen when building c++ . configure: error: No support for this host/target combination. make[1]: *** [Makefile:12511: configure-target-libstdc++-v3] Error 1 make[1]: Leaving directory '/gcc-build' make: *** [Makefile:962: all] Error 2 We edited libgcc/config.host to add support for our port; we are thinking there is a similar config file that needs to be edited to add support for our port in libstdc++ . Any idea which file need to be edited to support our port when libstdc++ is being built ?