strange problem building non-pure wheel for apple M1 arm64

[Robin Becker]

I use cibuildwheel to build extensions with a github action. For the macos 11.0 arm64 build I get a strange message from 
the load command. So I am looking for assistance to try and figure out what is going wrong.

The cibuild action uses the latest pip 21.2.4 and latest setuptools etc.

I use brew to install freetype version 2.11.1.

The compilations look like this
gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -g -arch 
arm64 -DRENDERPM_FT -DLIBART_COMPILATION -DLIBART_VERSION=2.3.21 -Isrc/rl_addons/renderPM 
-Isrc/rl_addons/renderPM/libart_lgpl -Isrc/rl_addons/renderPM/gt1 -I/usr/local/include/freetype2 
-I/Library/Frameworks/Python.framework/Versions/3.9/include/python3.9 -c src/rl_addons/renderPM/_renderPM.c -o 
build/temp.macosx-11.0-arm64-3.9/src/rl_addons/renderPM/_renderPM.o

this is the load command on multiple lines for readability the strange error is

gcc -bundle -undefined dynamic_lookup -g -arch arm64
	build/temp.macosx-11.0-arm64-3.9/src/rl_addons/renderPM/_renderPM.o
	build/temp.macosx-11.0-arm64-3.9/src/rl_addons/renderPM/gt1/gt1-dict.o
	build/temp.macosx-11.0-arm64-3.9/src/rl_addons/renderPM/gt1/gt1-namecontext.o
	'''''''other compiled code
	build/temp.macosx-11.0-arm64-3.9/src/rl_addons/renderPM/libart_lgpl/art_vpath_dash.o
	-L/usr/local/lib
	-L/usr/lib
	-L/Library/Frameworks/Python.framework/Versions/3.9/lib
	-lfreetype -o build/lib.macosx-11.0-arm64-3.9/reportlab/graphics/_renderPM.cpython-39-darwin.so

ld: warning: ignoring file /usr/local/lib/libfreetype.dylib, building for macOS-arm64 but attempting to link with file 
built for macOS-x86_64

The above message seems bizarre; everything is compiled for arm64, but gcc doesn't want to use an arm64 dylib.

Can macos experts assist?
--
Robin Becker