Comment 3 for bug 1991957

idna is a package required by hvac (used in layer-vault-kv) and also by aiohttp
idna >= 3.4 and beyond requires flit-core>3.2,<4 to build the idna wheel
flit-core (3.7.1) is encountering an issue pip installing itself into this environment.

A detailed view of the installation shows this error:
https://paste.ubuntu.com/p/Q9nvjPSWDv/

where pip seems to be generating a malformed subprocess call to itself for installing the flit-core package.

flit-core doesn't have any requirements (https://github.com/pypa/flit/blob/3.7.1/flit_core/pyproject.toml) -- but pip think that it should run the install command for those empty requirements which manifests the failure. This could be due a bug that's be since fixed in pip