The whole configuration `__init__.py` is type ignored: https://github.com/open-telemetry/opentelemetry-python/blob/ce269a36f1678deaa1c2053352499b34fa65f4ca/opentelemetry-api/src/opentelemetry/configuration/__init__.py#L15-L16 This file was created when `loader.py` was removed in #466 (which closes #313), but introduced new typing issues. - remove the type ignore - fix the type errors - upgrade mypy to most recent 0.770