Requirements for modern runtime support on Linux

[Jeremy Agostino]

Greetings. I’ve been struggling with issues related to conflicting exception 
types and non-fragile ABI support and I’ve realized that gnustep-base’s 
configure process is automatically disabled native ObjC exceptions and 
non-fragile ABI support due to some features tests failing. This is puzzling me 
because I am using clang and the latest libobjc2 and I was under the impression 
that this combination would allow for those features to be enabled. Is there 
anything else I have to do or provide to allow gnustep-base to build with 
support for native exceptions and the non-fragile ABI?

Here are the bits of my config.log that seem to be relevant:

configure:7519: checking for non-fragile-abi support
configure:7552: result: no

configure:7637: checking for objc_set_unexpected() in runtime
configure:7643: /Volumes/x-tools/clang —snip—
In file included from conftest.c:102:
In file included from ././config/config.set_unexpected.m:2:
/var/folders/1f/b4h58vtj2_10kj0rqd15mtq00000gn/T/conftest-5b0205.o: In function 
`main':
/Volumes/build/gnustep-base/././config/config.set_unexpected.m:6: undefined 
reference to `objc_set_unexpected'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
configure:7643: $? = 1
configure: failed program was:
—snip—
configure:7655: result: no

configure:7660: checking for _objc_unexpected_exception in runtime
configure:7683: result: no
configure:7693: Disabling native Objective-C exceptions because the ObjC runtime
configure:7695: has no way to set an uncaught exception handler.  Please install
configure:7697: a recent Objective-C runtime if you want to use them