So this is getting better and worse. :-) Seems that CC_FOR_BUILD is the native local gcc8 that was used to create the cross compiler and not the cross compiler itself. So with CC_FOR_BUILD=/usr/local/bin/gcc8 the process continues well into the gmp build where it blows up due to a complaint about gmp.h not existing? checking for _mulx_u64... cannot test, assume no checking for long double... yes checking format of `long double' floating point... IEEE quad, little endian checking for TLS support using C11... cannot test, assume no checking for TLS support... cannot test, assume no checking if __float128 with hex constants is supported... no checking for Static Assertion support... yes checking for library containing clock_gettime... none required checking for gmp.h... no configure: error: gmp.h can't be found, or is unusable. gmake[1]: *** [Makefile:5139: configure-mpfr] Error 1 gmake[1]: Leaving directory '/usr/home/dclarke/rv64g_local/build/gcc-8.2.0_rv64imafdc.005' gmake: *** [Makefile:906: all] Error 2 Right so ... gmp.h headers have to be installed somewhere for the target system? However the libs themselves do NOT need to exist? None of this is making any sense. dc
