Building GNUStep on OSX El Capitan. Why does it swear at ObjC Compiler?

Question

Objective-C

I like the Objective-C language and would like to write cross-platform programs in it. I found GNUStep on the Internet, downloaded the latest sources from the official site. gnustep-make compiled without problems. Now we need gnustep-base.
But, the problem is that gnustep-base doesn't compile on OSX. I read on the Internet that the native Apple LLVM is not compatible with gnustep. so installed gcc-5 via Homebew.
How I compile:

$./configure CC=gcc-5
checking build system type... i386-apple-darwin15.2.0
checking host system type... i386-apple-darwin15.2.0
checking target system type... i386-apple-darwin15.2.0
checking for GNUstep configuration file to use at runtime... /Library/GNUstep/GNUstep.conf
checking whether the GNUstep.conf file path can be set in the environment... yes
...
checking for gettid()... no
checking whether objc really works... no
I don't seem to be able to use your Objective-C compiler to produce
working binaries!  Please check your Objective-C compiler installation.
If you are using gcc-3.x make sure that your compiler's libgcc_s and libobjc
can be found by the dynamic linker - usually that requires you to play
with LD_LIBRARY_PATH or /etc/ld.so.conf.
Please refer to your compiler installation instructions for more help.
configure: error: The Objective-C compiler does not work or is not installed properly.