Re: Problem building GNAT CE 2021 on Mac Catalina

[Roger Mc <rogermcm2@gmail.com>]

I don't know what happened but the problem has changed even when rebuilding from scratch (original tar balls).

In src/gcc/Makefile.in change "path to the system headers on the build machine" to:
BUILD_SYSTEM_HEADER_DIR = /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include
then, from build directory:

../src/configure --enable-languages="c,ada" --with-gmp=/usr/local/Cellar/gmp/6.2.1 --with-mpfr=/usr/local/Cellar/mpfr/4.1.0 --with-mpc=/usr/local/Cellar/libmpc/1.1.0 --disable-nls
followed by make bootstrap produces:

checking whether /opt/GNAT/2021/obj/./gcc/xgcc -B/opt/GNAT/2021/obj/./gcc/ -B/usr/local/x86_64-apple-darwin19.6.0/bin/ -B/usr/local/x86_64-apple-darwin19.6.0/lib/ -isystem /usr/local/x86_64-apple-darwin19.6.0/include -isystem /usr/local/x86_64-apple-darwin19.6.0/sys-include   -fno-checking accepts -g... yes
checking for /opt/GNAT/2021/obj/./gcc/xgcc -B/opt/GNAT/2021/obj/./gcc/ -B/usr/local/x86_64-apple-darwin19.6.0/bin/ -B/usr/local/x86_64-apple-darwin19.6.0/lib/ -isystem /usr/local/x86_64-apple-darwin19.6.0/include -isystem /usr/local/x86_64-apple-darwin19.6.0/sys-include   -fno-checking option to accept ISO C89... unsupported
checking how to run the C preprocessor... /lib/cpp
configure: error: in `/opt/GNAT/2021/obj/x86_64-apple-darwin19.6.0/libgcc':
configure: error: C preprocessor "/lib/cpp" fails sanity check
See `config.log' for more details
make[2]: *** [configure-stage1-target-libgcc] Error 1
make[1]: *** [stage1-bubble] Error 2
make: *** [bootstrap] Error 2

Relevant part of    obj/x86_64-apple-darwin19.6.0/libgcc/config.log:
configure:4140: /lib/cpp  conftest.c
/opt/GNAT/2021/src/libgcc/configure: line 1528: /lib/cpp: No such file or directory
configure:4140: $? = 127
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME "GNU C Runtime Library"
| #define PACKAGE_TARNAME "libgcc"
| #define PACKAGE_VERSION "1.0"
| #define PACKAGE_STRING "GNU C Runtime Library 1.0"
| #define PACKAGE_BUGREPORT ""
| #define PACKAGE_URL "http://www.gnu.org/software/libgcc/"
| /* end confdefs.h.  */
| #ifdef __STDC__
| # include <limits.h>
| #else
| # include <assert.h>
| #endif
| 		     Syntax error
configure:4170: error: in `/opt/GNAT/2021/obj/x86_64-apple-darwin19.6.0/libgcc':
configure:4172: error: C preprocessor "/lib/cpp" fails sanity check
See `config.log' for more details

Thanks for ongoing advice.