[hakarrr]

Problem

RepositoryIni.__getitem__ translates a missing option into KeyError, as introduced in #153 for cascading repositories. But a valid empty INI file, or one containing only another section, instead raises NoSectionError. The repository reports that the key is absent, yet a fallback loop catching KeyError cannot continue to the next repository.

Change

Translate NoSectionError alongside NoOptionError, preserving the requested key in KeyError.args. Parsing and interpolation errors remain unchanged. This does not change environment-variable precedence or the scope of #180.

Added five test cases: empty and unrelated-section files for direct lookup and repository fallback, plus a control that interpolation errors are not hidden. Four cases fail on the unchanged base. No existing tests or CI settings are changed.

Validation

• Unchanged baseline: 67 tests pass on Python 3.11.
• Full suite with regressions: 72 tests pass on CPython 3.9, 3.10, 3.11 and 3.12.
• Combined branch/line coverage: 95% on Python 3.11.
• New test module passes flake8; wheel/source distribution build and git diff --check pass.
• Tests use only the repository's existing pytest/mock dependencies and fabricated in-memory INI content. No external services or personal configuration are accessed.

Python 2.7, 3.6-3.8, PyPy and other operating systems were not available for execution. The production imports and tests retain the project's older-Python-compatible syntax.