No need to have a gcc with gcc-core... With gcc 7.5.0 I get:     -o build/gengtype.o ../../gpc3/gcc-7.5.0/gcc/gengtype.c g++ -std=gnu++98 -c   -g -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common -Wno-error -DHAVE_CONFIG_H -DGENERATOR_FILE -fno-PIE -I. -Ibuild -I../../gpc3/gcc-7.5.0/gcc -I../../gpc3/gcc-7.5.0/gcc/build -I../../gpc3/gcc-7.5.0/gcc/../include  -I../../gpc3/gcc-7.5.0/gcc/../libcpp/include  \     -o build/gengtype-lex.o ../../gpc3/gcc-7.5.0/gcc/gengtype-lex.c gengtype-lex.c: In function ‘int yy_get_next_buffer()’: gengtype-lex.c:1343:18: warning: comparison of integer expressions of different signedness: ‘size_t’ {aka ‘long unsigned int’} and ‘int’ [-Wsign-compare] gengtype-lex.c:2150:3: note: in expansion of macro ‘YY_INPUT’ gengtype-lex.c: In function ‘yy_buffer_state* yy_scan_bytes(const char*, yy_size_t)’: gengtype-lex.c:2658:17: warning: comparison of integer expressions of different signedness: ‘int’ and ‘yy_size_t’ {aka ‘long unsigned int’} [-Wsign-compare] /space/rguenther/gcc-7.5.0/gcc-7.5.0/gcc/gengtype-lex.l: In function ‘int yylex(const char**)’: gengtype-lex.c:365:15: warning: this statement may fall through [-Wimplicit-fallthrough=] /space/rguenther/gcc-7.5.0/gcc-7.5.0/gcc/gengtype-lex.l:117:1: note: in expansion of macro ‘YY_DO_BEFORE_ACTION’ /space/rguenther/gcc-7.5.0/gcc-7.5.0/gcc/gengtype-lex.l:113:1: note: here gengtype-lex.c:365:15: warning: this statement may fall through [-Wimplicit-fallthrough=] /space/rguenther/gcc-7.5.0/gcc-7.5.0/gcc/gengtype-lex.l:134:1: note: in expansion of macro ‘YY_DO_BEFORE_ACTION’ /space/rguenther/gcc-7.5.0/gcc-7.5.0/gcc/gengtype-lex.l:131:1: note: here g++ -std=gnu++98 -c   -g -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H -DGENERATOR_FILE -fno-PIE -I. -Ibuild -I../../gpc3/gcc-7.5.0/gcc -I../../gpc3/gcc-7.5.0/gcc/build -I../../gpc3/gcc-7.5.0/gcc/../include  -I../../gpc3/gcc-7.5.0/gcc/../libcpp/include  \     -o build/gengtype-parse.o ../../gpc3/gcc-7.5.0/gcc/gengtype-parse.c g++ -std=gnu++98 -c   -g -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H -DGENERATOR_FILE -fno-PIE -I. -Ibuild -I../../gpc3/gcc-7.5.0/gcc -I../../gpc3/gcc-7.5.0/gcc/build -I../../gpc3/gcc-7.5.0/gcc/../include  -I../../gpc3/gcc-7.5.0/gcc/../libcpp/include  \     -o build/gengtype-state.o ../../gpc3/gcc-7.5.0/gcc/gengtype-state.c g++ -std=gnu++98 -c   -g -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H -DGENERATOR_FILE -fno-PIE -I. -Ibuild -I../../gpc3/gcc-7.5.0/gcc -I../../gpc3/gcc-7.5.0/gcc/build -I../../gpc3/gcc-7.5.0/gcc/../include  -I../../gpc3/gcc-7.5.0/gcc/../libcpp/include  \ -DBASEVER="\"7.5.0\"" -DDATESTAMP="\"\"" \ -DREVISION="\"\"" \ -DDEVPHASE="\"\"" -DPKGVERSION="\"(GCC) \"" \ -DBUGURL="\"<https://gcc.gnu.org/bugs/>\"" -o build/version.o ../../gpc3/gcc-7.5.0/gcc/version.c g++ -std=gnu++98   -g -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H -DGENERATOR_FILE -fno-PIE -static-libstdc++ -static-libgcc  -no-pie -o build/gengtype \     build/gengtype.o build/errors.o build/gengtype-lex.o build/gengtype-parse.o build/gengtype-state.o build/version.o ../build-x86_64-pc-linux-gnu/libiberty/libiberty.a LC_ALL=C ; export LC_ALL ; \ gawk -f ../../gpc3/gcc-7.5.0/gcc/opt-gather.awk ../../gpc3/gcc-7.5.0/gcc/ada/gcc-interface/lang.opt ../../gpc3/gcc-7.5.0/gcc/brig/lang.opt ../../gpc3/gcc-7.5.0/gcc/fortran/lang.opt ../../gpc3/gcc-7.5.0/gcc/go/lang.opt ../../gpc3/gcc-7.5.0/gcc/lto/lang.opt ../../gpc3/gcc-7.5.0/gcc/p/lang.opt ../../gpc3/gcc-7.5.0/gcc/c-family/c.opt ../../gpc3/gcc-7.5.0/gcc/common.opt ../../gpc3/gcc-7.5.0/gcc/config/fused-madd.opt ../../gpc3/gcc-7.5.0/gcc/config/i386/i386.opt ../../gpc3/gcc-7.5.0/gcc/config/gnu-user.opt ../../gpc3/gcc-7.5.0/gcc/config/linux.opt ../../gpc3/gcc-7.5.0/gcc/config/linux-android.opt > tmp-optionlist /bin/bash ../../gpc3/gcc-7.5.0/gcc/../move-if-change tmp-optionlist optionlist echo timestamp > s-options gawk -f ../../gpc3/gcc-7.5.0/gcc/opt-functions.awk -f ../../gpc3/gcc-7.5.0/gcc/opt-read.awk \        -f ../../gpc3/gcc-7.5.0/gcc/opth-gen.awk \        < optionlist > tmp-options.h /bin/bash ../../gpc3/gcc-7.5.0/gcc/../move-if-change tmp-options.h options.h echo timestamp > s-options-h /bin/bash ../../gpc3/gcc-7.5.0/gcc/../move-if-change tmp-gi.list gtyp-input.list echo timestamp > s-gtyp-input build/gengtype  \                     -S ../../gpc3/gcc-7.5.0/gcc -I gtyp-input.list -w tmp-gtype.state ../../gpc3/gcc-7.5.0/gcc/p/module.c:294: option `length' may not be applied to arrays of atomic types make[3]: *** [Makefile:2573 : s-gtype] Erreur 1 make[3] : on quitte le répertoire « /home/paul/gpc-build3/gcc » make[2]: *** [Makefile:4548 : all-stage1-gcc] Erreur 2 make[2] : on quitte le répertoire « /home/paul/gpc-build3 » make[1]: *** [Makefile:23803 : stage1-bubble] Erreur 2 make[1] : on quitte le répertoire « /home/paul/gpc-build3 » make: *** [Makefile:934 : all] Erreur 2 paul@jacko:~/gpc-build3$ This time, I don't understand what the compiler wants me to do.