How to config M1 Mac gcc build of cpp_library

I have tried several hours of google and gradle source code research. Breaking down and asking for help directly.

I have a cpp-library build that works fine on debian, centos, and intel mac. Want to do same on an M1/aarch64 mac (physically on the mac, not a cross compile). /usr/bin/gcc and ld confirmed present.

How can I configure model/platform/toolchain/… to make this happen?

Currently at this error:

No tool chain has support to build C++ for host operating system ‘Mac OS X’ architecture ‘aarch64’:
- Tool chain ‘gcc’ (GNU GCC):
- Don’t know how to build for host operating system ‘Mac OS X’ architecture ‘aarch64’.

Thank you,
Matthew

P.S. currently on 7.4.2 because 7.5.1 had new, but unrelated issues.