Re: "undefined reference to ’objc_msgSend’"

[David Chisnall]

On 04/04/2019 13:52, Scott Little wrote:
> →    -L/usr/lib/gcc/x86_64-linux-gnu/7/libobjc.so \

This looks very much as if you are linking the old GCC libobjc, which 
doesn't provide an objc_msgSend implementation.  If you wish to use 
this, then you must use -fobjc-runtime=gcc, not -fobjc-runtime=gnustep.

-fobjc-runtime=gnustep is not recommended without an explicit version 
(e.g. -fobjc-runtime=gnustep-2.0).

David