gnuconfig and runtime 1.9/ARC issue

[Johannes Brakensiek]

Hello everyone,

currently I'm learning ObjC and Cocoa and I'm digging into GNUstep for
cross platform development.

I compiled GNUstep from scratch using a modified version of Patryk
Laurent's script, which is documented by this repo:
https://github.com/Letterus/gnustep-build-debian/blob/master/GNUstep-buildon-debian.sh

It's the 1.9 runtime compiled using clang 6.0 on Debian 9 stretch.

Apps work fine so far, but now I wanted to compile one with ARC enabled.
I added to the makefile:

OBJCFLAGS = -fobjc-arc

But upon make I get this error:

error: -fobjc-arc is not supported on platforms using the legacy runtime

To check the selected platform I checked the output of "gnustep-config
--objc-flags", which is this:

-MMD -MP -DGNUSTEP -DGNUSTEP_BASE_LIBRARY=1 -DGNU_GUI_LIBRARY=1
-DGNU_RUNTIME=1 -DGNUSTEP_BASE_LIBRARY=1 -fno-strict-aliasing
-fexceptions -fobjc-exceptions -D_NATIVE_OBJC_EXCEPTIONS -pthread -fPIC
-DDEBUG -fno-omit-frame-pointer -Wall -DGSWARN -DGSDIAGNOSE -Wno-import
-g -fblocks -fobjc-runtime=gnustep-1.9 -fobjc-runtime=gcc
-fconstant-string-class=NSConstantString -I.
-I/home/joey/GNUstep/Library/Headers
-I/usr/GNUstep/Local/Library/Headers -I/usr/GNUstep/System/Library/Headers

I wonder where this "-fobjc-runtime=gcc" comes from, if it is the cause
of the issue and how to get rid of it?

Do you have any hints?

Thanks and regards,
Johannes