Empty key sets give the wrong exception. The error is here:

When keys is the empty list, not keys is true so the second check is never reached (unless some list subclass overrides __bool__).

Expected Result

Should raise PyJWKSetError("The JWK Set did not contain any keys").

Actual Result

Raises PyJWKSetError("Invalid JWK Set value").

Reproduction Steps

import jwt
jwt.PyJWKSet.from_dict({"keys": []})