g95 configure fails Configuration arm-apple-darwin23.6.0 not supported

[jgrg (James Gilbert)]

Building R, which builds g95, the configure step of g95 fails:

:info:configure checking if mkdir takes one argument... no
:info:configure *** Configuration arm-apple-darwin23.6.0 not supported
:info:configure make[2]: *** [configure-stage1-gcc] Error 1
:info:configure make[1]: *** [stage1-bubble] Error 2
:info:configure make: *** [all] Error 2
:info:configure Command failed: export CC="/usr/bin/clang";  export CPPFLAGS="-I/opt/local/include";  export CFLAGS="-Os -std=gnu89 -arch arm64";  export CFLAGS_FOR_BUILD="-Os -std=gnu89 -arch arm64";  export CFLAGS_FOR_TARGET="-Os -std=gnu89";  export LDFLAGS="-L/opt/local/lib -Wl,-headerpad_max_install_names -arch arm64";  export MACOSX_DEPLOYMENT_TARGET="14.0";  export MAKEINFO=missing; ../configure --prefix=/opt/local/lib/g95//4.2.4  --enable-languages=c  --disable-multilib  --with-included-gettext  --with-libiconv=/opt/local  --libdir=/opt/local/lib/g95//4.2.4  --with-as=/opt/local/bin/as  --with-ld=/opt/local/bin/ld  --with-nm=/opt/local/bin/nm  --build= --host=;  make
:info:configure Exit code: 2

If I cd to what I guess is the working directory:

/opt/local/var/macports/sources/rsync.macports.org/macports/release/tarballs/ports/lang/g95/work/g95-0.93/libf95.a-0.93

and run the failed command line above it prints:

...
checking for alloca... yes
host = arm-apple-darwin23.6.0
configure: error: Unknown floating point architecture
make: *** No targets specified and no makefile found.  Stop.

[jgrg (James Gilbert)]

Oh, hang on, this makes sense. The g95 compiler has never worked on ARM. This is a problem with the R port, not g95 which is Intel only. This is the same problem as ticket #71068