Hello, I am trying to build GCC6.3.0 on Ubuntu20.04 and can't seem to understand/fix the errors. I downloaded the tar file(tried from multiple mirrors, always same error), untarred it, within this untarred directory ran ./contrib/download_prerequisites it downloads and creates the required shortcuts. Then I get out of this directory, create a new directory "gccbuild",within this directory, I run $PWD/../gcc-6.3.0/configure --prefix=$HOME/GCC-6.3.0 --enable-languages=c,c++,fortran,go the output is as follows, a lot of no's but I don't think if that's the issue. checking build system type... x86_64-pc-linux-gnu checking host system type... x86_64-pc-linux-gnu checking target system type... x86_64-pc-linux-gnu checking for a BSD-compatible install... /usr/bin/install -c checking whether ln works... yes checking whether ln -s works... yes checking for a sed that does not truncate output... /usr/bin/sed checking for gawk... no checking for mawk... mawk checking for libatomic support... yes checking for libcilkrts support... yes checking for libitm support... yes checking for libsanitizer support... yes checking for libvtv support... yes checking for libmpx support... yes checking for gcc... gcc checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking for g++... g++ checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking whether g++ accepts -static-libstdc++ -static-libgcc... yes checking for gnatbind... no checking for gnatmake... no checking whether compiler driver understands Ada... no checking how to compare bootstrapped objects... cmp --ignore-initial=16 $$f1 $$f2 checking for objdir... .libs configure: WARNING: using in-tree isl, disabling version check 'c++' language required by 'go' in stage 1; enabling *** This configuration is not supported in the following subdirectories: gnattools target-libada target-zlib target-libjava target-libobjc target-liboffloadmic target-boehm-gc (Any other directories should still work fine.) checking for default BUILD_CONFIG... bootstrap-debug checking for --enable-vtable-verify... no checking for bison... no checking for byacc... no checking for yacc... no checking for bison... no checking for gm4... no checking for gnum4... no checking for m4... no checking for flex... no checking for lex... no checking for flex... no checking for makeinfo... makeinfo checking for expect... no checking for runtest... no checking for ar... ar checking for as... as checking for dlltool... no checking for ld... ld checking for lipo... no checking for nm... nm checking for ranlib... ranlib checking for strip... strip checking for windres... no checking for windmc... no checking for objcopy... objcopy checking for objdump... objdump checking for readelf... readelf checking for cc... cc checking for c++... c++ checking for gcc... gcc checking for gcj... no checking for gfortran... no checking for gccgo... no checking for ar... no checking for ar... ar checking for as... no checking for as... as checking for dlltool... no checking for dlltool... no checking for ld... no checking for ld... ld checking for lipo... no checking for lipo... no checking for nm... no checking for nm... nm checking for objcopy... no checking for objcopy... objcopy checking for objdump... no checking for objdump... objdump checking for ranlib... no checking for ranlib... ranlib checking for readelf... no checking for readelf... readelf checking for strip... no checking for strip... strip checking for windres... no checking for windres... no checking for windmc... no checking for windmc... no checking where to find the target ar... host tool checking where to find the target as... host tool checking where to find the target cc... just compiled checking where to find the target c++... just compiled checking where to find the target c++ for libstdc++... just compiled checking where to find the target dlltool... host tool checking where to find the target gcc... just compiled checking where to find the target gcj... host tool checking where to find the target gfortran... just compiled checking where to find the target gccgo... just compiled checking where to find the target ld... host tool checking where to find the target lipo... host tool checking where to find the target nm... host tool checking where to find the target objcopy... host tool checking where to find the target objdump... host tool checking where to find the target ranlib... host tool checking where to find the target readelf... host tool checking where to find the target strip... host tool checking where to find the target windres... host tool checking where to find the target windmc... host tool checking whether to enable maintainer-specific portions of Makefiles... no configure: creating ./config.status config.status: creating Makefile Then, I run make, and the following are few last lines of the output: /home/mohana/GCC-6.3.0/x86_64-pc-linux-gnu/include -isystem /home/mohana/GCC-6.3.0/x86_64-pc-linux-gnu/sys-include -g -O2 -O2 -g -O2 -DIN_GCC -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -fpic -mlong-double-80 -DUSE_ELF_SYMVER -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector -fpic -mlong-double-80 -DUSE_ELF_SYMVER -I. -I. -I../.././gcc -I/home/mohana/gccbuild/../gcc-6.3.0/libgcc -I/home/mohana/gccbuild/../gcc-6.3.0/libgcc/. -I/home/mohana/gccbuild/../gcc-6.3.0/libgcc/../gcc -I/home/mohana/gccbuild/../gcc-6.3.0/libgcc/../include -I/home/mohana/gccbuild/../gcc-6.3.0/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS -DUSE_TLS -o _fixunssfsi.o -MT _fixunssfsi.o -MD -MP -MF _fixunssfsi.dep -DL_fixunssfsi -c /home/mohana/gccbuild/../gcc-6.3.0/libgcc/libgcc2.c -fvisibility=hidden -DHIDE_EXPORTS make[5]: Leaving directory '/home/mohana/gccbuild/x86_64-pc-linux-gnu/32/libgcc' make[4]: *** [Makefile:1161: multi-do] Error 1 make[4]: Leaving directory '/home/mohana/gccbuild/x86_64-pc-linux-gnu/libgcc' make[3]: *** [Makefile:120: all-multi] Error 2 make[3]: *** Waiting for unfinished jobs.... make[3]: Leaving directory '/home/mohana/gccbuild/x86_64-pc-linux-gnu/libgcc' make[2]: *** [Makefile:20436: all-stage1-target-libgcc] Error 2 make[2]: Leaving directory '/home/mohana/gccbuild' make[1]: *** [Makefile:25715: stage1-bubble] Error 2 Any leads will be highly appreciated! Thank you, Mohana