Mac M1 support

The Mac M1 series seems to be unsupported. Here is my debug output:

2021-01-21 16:49:22,365 ERROR:usb.libloader:Libusb 1 (/opt/homebrew/Cellar/libusb/1.0.24/lib/libusb-1.0.dylib) could not be loaded
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/usb/libloader.py", line 118, in load_library
    return ctypes.CDLL(lib)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/ctypes/__init__.py", line 374, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: dlopen(/opt/homebrew/Cellar/libusb/1.0.24/lib/libusb-1.0.dylib, 6): no suitable image found.  Did find:
	/opt/homebrew/Cellar/libusb/1.0.24/lib/libusb-1.0.dylib: mach-o, but wrong architecture
	/opt/homebrew/Cellar/libusb/1.0.24/lib/libusb-1.0.0.dylib: mach-o, but wrong architecture
	/opt/homebrew/Cellar/libusb/1.0.24/lib/libusb-1.0.dylib: mach-o, but wrong architecture
	/opt/homebrew/Cellar/libusb/1.0.24/lib/libusb-1.0.0.dylib: mach-o, but wrong architecture
2021-01-21 16:49:22,367 ERROR:usb.backend.libusb1:Error loading libusb 1.0 backend
2021-01-21 16:49:22,367 ERROR:usb.libloader:'OpenUSB library' could not be found
2021-01-21 16:49:22,367 ERROR:usb.backend.openusb:Error loading OpenUSB backend
2021-01-21 16:49:22,369 ERROR:usb.libloader:'Libusb 0' could not be found
2021-01-21 16:49:22,369 ERROR:usb.backend.libusb0:Error loading libusb 0.1 backend
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/usb/core.py", line 1299, in find
    raise NoBackendError('No backend available')
usb.core.NoBackendError: No backend available

Please add this support.

[mellow-hype]

For anyone else still having this issue, I manage python installations with pyenv and installed libusb with homebrew and was having this issue as well. I was finally able to resolve the issue by creating a new symlink in /usr/local/lib named libusb.dylib linked to the existing link created by homebrew.

ln -s /opt/homebrew/lib/libusb-1.0.0.dylib //usr/local/lib/libusb.dylib

It seems the expected file name is libusb.dylib.

[mellow-hype]

hey @jonasmalacofilho – in case it helps, I recently installed libusb via homebrew on a new M1 mac and ended up running into either the same or similar issue and resolving it by using export DYLD_LIBRARY_PATH=/opt/homebrew/lib prior to running the package that was leveraging libusb. I had forgotten about the fix I had previously noted above. Looking at both “fixes”, I think the issue may be in the custom directory homebrew uses on M1s (/opt/homebrew) and it not being in the default dyld search path (at least not for non-homebrew Python installations).