I am getting:
gcc -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-long -DHAVE_CONFIG_H -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-long -pedantic -Wno-long-long -Wno-traditional -I. -I. -I../../gpc1/gcc-3.4.6/gcc -I../../gpc1/gcc-3.4.6/gcc/. -I../../gpc1/gcc-3.4.6/gcc/../include -DGPC -DGPC_UNITS_DIR=\"/usr/local/lib/gcc/x86_64-unknown-linux-gnu/3.4.6/units\" -I../../gpc1/gcc-3.4.6/gcc/p -o gpc1 p/parse.o p/declarations.o p/expressions.o p/gpc-lex.o p/lang.o p/module.o p/objects.o p/options.o p/predef.o p/statements.o p/typecheck.o p/types.o p/convert.o p/dbxout.o p/dwarf2out.o p/expr.o p/fold-const.o p/function.o p/integrate.o p/optabs.o p/stor-layout.o p/toplev.o p/tree.o p/stmt.o p/emit-rtl.o p/varasm.o p/version.o p/gpcpp.o p/plant.o p/diagnostic.o attribs.o main.o libbackend.a ../libiberty/libiberty.a ../libiberty/libiberty.a
/home/paul/opt/GNAT/2020/bin/../libexec/gcc/x86_64-pc-linux-gnu/9.3.1/ld: ../libiberty/libiberty.a(choose-temp.o): in function `choose_temp_base':
/home/paul/gpc1-build/libiberty/../../gpc1/gcc-3.4.6/libiberty/choose-temp.c:68: warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
(SHLIB_LINK='/home/paul/gpc1-build/gcc/xgcc -B/home/paul/gpc1-build/gcc/ -B/usr/local/x86_64-unknown-linux-gnu/bin/ -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem /usr/local/x86_64-unknown-linux-gnu/include -isystem /usr/local/x86_64-unknown-linux-gnu/sys-include -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -Wno-error -isystem ./include -fPIC -g -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -shared -nodefaultlibs -Wl,--soname=@shlib_so_name@.so.1 -Wl,--version-script=@shlib_map_file@ -o @shlib_dir@@shlib_so_name@.so.1.tmp @multilib_flags@ @shlib_objs@ -lc && rm -f @shlib_base_name@.so && if [ -f @shlib_dir@@shlib_so_name@.so.1 ]; then mv -f @shlib_dir@@shlib_so_name@.so.1 @shlib_dir@@shlib_so_name@.so.1.backup; else true; fi && mv @shlib_dir@@shlib_so_name@.so.1.tmp @shlib_dir@@shlib_so_name@.so.1 && ln -s @shlib_dir@@shlib_so_name@.so.1 @shlib_base_name@.so' \
SHLIB_MULTILIB=''; \
gcc -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-long -Wno-error -DHAVE_CONFIG_H -I. -I. -I../../gpc1/gcc-3.4.6/gcc -I../../gpc1/gcc-3.4.6/gcc/. -I../../gpc1/gcc-3.4.6/gcc/../include \
-DSTANDARD_STARTFILE_PREFIX=\"../../../\" -DSTANDARD_EXEC_PREFIX=\"/usr/local/lib/gcc/\" -DSTANDARD_LIBEXEC_PREFIX=\"/usr/local/libexec/gcc/\" -DDEFAULT_TARGET_VERSION=\"3.4.6\" -DDEFAULT_TARGET_MACHINE=\"x86_64-unknown-linux-gnu\" -DSTANDARD_BINDIR_PREFIX=\"/usr/local/bin/\" -DTOOLDIR_BASE_PREFIX=\"../../../../\" `test "X${SHLIB_LINK}" = "X" || test "yes" != "yes" || echo "-DENABLE_SHARED_LIBGCC"` `test "X${SHLIB_MULTILIB}" = "X" || echo "-DNO_SHARED_LIBGCC_MULTILIB"` \
-c ../../gpc1/gcc-3.4.6/gcc/gcc.c -o gcc.o)
../../gpc1/gcc-3.4.6/gcc/gcc.c: In function 'do_spec_1':
../../gpc1/gcc-3.4.6/gcc/gcc.c:5118:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
5118 | error ("warning: use of obsolete %%[ operator in specs");
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gpc1/gcc-3.4.6/gcc/gcc.c:5119:4: note: here
5119 | case '(':
| ^~~~
(SHLIB_LINK='/home/paul/gpc1-build/gcc/xgcc -B/home/paul/gpc1-build/gcc/ -B/usr/local/x86_64-unknown-linux-gnu/bin/ -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem /usr/local/x86_64-unknown-linux-gnu/include -isystem /usr/local/x86_64-unknown-linux-gnu/sys-include -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -fPIC -g -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -shared -nodefaultlibs -Wl,--soname=@shlib_so_name@.so.1 -Wl,--version-script=@shlib_map_file@ -o @shlib_dir@@shlib_so_name@.so.1.tmp @multilib_flags@ @shlib_objs@ -lc && rm -f @shlib_base_name@.so && if [ -f @shlib_dir@@shlib_so_name@.so.1 ]; then mv -f @shlib_dir@@shlib_so_name@.so.1 @shlib_dir@@shlib_so_name@.so.1.backup; else true; fi && mv @shlib_dir@@shlib_so_name@.so.1.tmp @shlib_dir@@shlib_so_name@.so.1 && ln -s @shlib_dir@@shlib_so_name@.so.1 @shlib_base_name@.so' \
SHLIB_MULTILIB=''; \
gcc -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-long -DHAVE_CONFIG_H -I. -I. -I../../gpc1/gcc-3.4.6/gcc -I../../gpc1/gcc-3.4.6/gcc/. -I../../gpc1/gcc-3.4.6/gcc/../include \
-DSTANDARD_STARTFILE_PREFIX=\"../../../\" -DSTANDARD_EXEC_PREFIX=\"/usr/local/lib/gcc/\" -DSTANDARD_LIBEXEC_PREFIX=\"/usr/local/libexec/gcc/\" -DDEFAULT_TARGET_VERSION=\"3.4.6\" -DDEFAULT_TARGET_MACHINE=\"x86_64-unknown-linux-gnu\" -DSTANDARD_BINDIR_PREFIX=\"/usr/local/bin/\" -DTOOLDIR_BASE_PREFIX=\"../../../../\" `test "X${SHLIB_LINK}" = "X" || test "yes" != "yes" || echo "-DENABLE_SHARED_LIBGCC"` `test "X${SHLIB_MULTILIB}" = "X" || echo "-DNO_SHARED_LIBGCC_MULTILIB"` \
-c ../../gpc1/gcc-3.4.6/gcc/gccspec.c -o gccspec.o)
gcc -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -pedantic -Wno-long-long -DHAVE_CONFIG_H -o xgcc gcc.o gccspec.o intl.o \
prefix.o version.o ../libiberty/libiberty.a
/home/paul/gpc1-build/gcc/xgcc -B/home/paul/gpc1-build/gcc/ -B/usr/local/x86_64-unknown-linux-gnu/bin/ -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem /usr/local/x86_64-unknown-linux-gnu/include -isystem /usr/local/x86_64-unknown-linux-gnu/sys-include -dumpspecs > tmp-specs
mv tmp-specs specs
cd ../../gpc1/gcc-3.4.6/gcc/p/rts && make -f Makefile.in srcdir=. GCC_VERSION="3.4.6" SHELL="/bin/sh" CFLAGS="-g -O2" PFLAGS="" AR_FLAGS="rc" RTSFLAGS="" GPC_DESTDIR="../.." AR="ar" RANLIB="ranlib" RANLIB_TEST="" generated-files
make[2] : on entre dans le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
make[2]: rien à faire pour « generated-files ».
make[2] : on quitte le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
cd ../../gpc1/gcc-3.4.6/gcc/p/rts && make -f Makefile.in srcdir=. GCC_VERSION="3.4.6" SHELL="/bin/sh" CFLAGS="-g -O2" PFLAGS="" AR_FLAGS="rc" RTSFLAGS="" GPC_DESTDIR="../.." AR="ar" RANLIB="ranlib" RANLIB_TEST="" generated-files
make[2] : on entre dans le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
make[2]: rien à faire pour « generated-files ».
make[2] : on quitte le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
cd ../../gpc1/gcc-3.4.6/gcc/p/rts && make -f Makefile.in srcdir=. GCC_VERSION="3.4.6" SHELL="/bin/sh" CFLAGS="-g -O2" PFLAGS="" AR_FLAGS="rc" RTSFLAGS="" GPC_DESTDIR="../.." AR="ar" RANLIB="ranlib" RANLIB_TEST="" generated-files
make[2] : on entre dans le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
make[2]: rien à faire pour « generated-files ».
make[2] : on quitte le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
cd ../../gpc1/gcc-3.4.6/gcc/p/rts && make -f Makefile.in srcdir=. GCC_VERSION="3.4.6" SHELL="/bin/sh" CFLAGS="-g -O2" PFLAGS="" AR_FLAGS="rc" RTSFLAGS="" GPC_DESTDIR="../.." AR="ar" RANLIB="ranlib" RANLIB_TEST="" generated-files
make[2] : on entre dans le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
make[2]: rien à faire pour « generated-files ».
make[2] : on quitte le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
cd ../../gpc1/gcc-3.4.6/gcc/p/rts && make -f Makefile.in srcdir=. GCC_VERSION="3.4.6" SHELL="/bin/sh" CFLAGS="-g -O2" PFLAGS="" AR_FLAGS="rc" RTSFLAGS="" GPC_DESTDIR="../.." AR="ar" RANLIB="ranlib" RANLIB_TEST="" generated-files
make[2] : on entre dans le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
make[2]: rien à faire pour « generated-files ».
make[2] : on quitte le répertoire « /home/paul/gpc1/gcc-3.4.6/gcc/p/rts »
[ -d "../../gpc1/gcc-3.4.6/gcc/p/doc/info" ] || ../../gpc1/gcc-3.4.6/gcc/p/script/mkdir-p "../../gpc1/gcc-3.4.6/gcc/p/doc/info"
LANG=hr_HR LC_ALL=hr_HR makeinfo --split-size=5000000 -I ../../gpc1/gcc-3.4.6/gcc/p/doc -I ../../gpc1/gcc-3.4.6/gcc/p/doc/hr -I ../../gpc1/gcc-3.4.6/gcc/p/doc/generated -I ../../gpc1/gcc-3.4.6/gcc/p/doc/en -o ../../gpc1/gcc-3.4.6/gcc/p/doc/info/gpc-hr.info \
../../gpc1/gcc-3.4.6/gcc/p/doc/hr/gpc.texi
utf8 "\xE8" does not map to Unicode at /usr/share/texinfo/Texinfo/ParserNonXS.pm line 1796, <FH> line 3.
Malformed UTF-8 character: \xe8\x6e\x69 (unexpected non-continuation byte 0x6e, immediately after start byte 0xe8; need 3 bytes, got 1) in pattern match (m//) at /usr/share/texinfo/Texinfo/ParserNonXS.pm line 3364.
Malformed UTF-8 character (fatal) at /usr/share/texinfo/Texinfo/ParserNonXS.pm line 3364.
make[1]: *** [../../gpc1/gcc-3.4.6/gcc/p/Make-lang.in:844 : ../../gpc1/gcc-3.4.6/gcc/p/doc/info/gpc-hr.info] Erreur 25
make[1] : on quitte le répertoire « /home/paul/gpc1-build/gcc »
make: *** [Makefile:23375 : all-gcc] Erreur 2
paul@jacko:~/gpc1-build$
At first I had tought it was because I did not have hr locale, but I did "sudo dpkg-reconfigure locales" where I included hr locales.