I have a classic snap that defines a python package and I am using the core20 version of the python plugin. When building I see this error: + python3 -m venv /home/ubuntu/vendor-util/parts/vendor-util/install + [ -f setup.py ] + pip install -U . Building wheels for collected packages: vendorutil   Building wheel for vendorutil (setup.py) ... error   ERROR: Command errored out with exit status 1:    command: /home/ubuntu/vendor-util/parts/vendor-util/install/bin/python3 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-req-build-7b50_eez/setup.py'"'"'; __file__='"'"'/tmp/pip-req-build-7b50_eez/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /tmp/pip-wheel-v2nf2nj8        cwd: /tmp/pip-req-build-7b50_eez/   Complete output (6 lines):   usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]      or: setup.py --help [cmd1 cmd2 ...]      or: setup.py --help-commands      or: setup.py cmd --help   error: invalid command 'bdist_wheel'   ----------------------------------------   ERROR: Failed building wheel for vendorutil   Running setup.py clean for vendorutil Failed to build vendorutil The failure goes away when I add 'wheel' to python-packages, but I do not know why that is needed if that is used just for packaging and I do not want it in the snap. Futhermore, staging the wheel package instead does not fix the problem. I am not sure why creating the wheel happens from the install folder of the part.