python-poetry/poetry · error · PoetryError

At least one source must not be configured as 'explicit'.

Error message

At least one source must not be configured as 'explicit'.

What it means

`PoetryError` from `create_pool` (factory.py:198-201) when every configured source is marked `priority = "explicit"`, leaving the pool with no usable repository. Explicit sources are only consulted when directly named, so resolving any unqualified dependency would be impossible.

Solutions

1. Set at least one source to `priority = "primary"` (the default) or `"secondary"`.
2. Remove `priority = "explicit"` from the source you want to serve as default.
3. If PyPI should remain available, do not mark its entry explicit.

Example fix

# before
[[tool.poetry.source]]
name = "pypi"
priority = "explicit"
# after
[[tool.poetry.source]]
name = "pypi"
priority = "primary"

sources = poetry.local_config.get("source", [])
non_explicit = [s for s in sources if s.get("priority", "primary") != "explicit"]
if not non_explicit:
    raise SystemExit("mark at least one source as primary or secondary")

def has_non_explicit_source(sources: list[dict]) -> bool:
    return any(s.get("priority", "primary") != "explicit" for s in sources)

When it happens

Trigger: In pyproject.toml `[[tool.poetry.source]]` all entries set `priority = "explicit"`; PyPI was also re-added as explicit.

Common situations: Locking down to private indexes but accidentally marking the primary one explicit; migrating a config and flipping all sources to explicit.

Related errors

• Missing [name] in source.
• A repository with name
• Package ( ) not found.
• Repository " " does not exist.
• RepositoryPool can not remove unknown repository

AI-assisted analysis of python-poetry/poetry@92b74dcfe3 (2026-08-04). Data as JSON: /api/errors/656984f8184c59fb. Report an issue: GitHub.

Appendix: source

Thrown at src/poetry/factory.py:199

            pool.add_repository(repository, priority=priority)
            if repository.name.lower() == "pypi":
                explicit_pypi = True

        # Only add PyPI if no primary repository is configured
        if not explicit_pypi:
            if pool.has_primary_repositories():
                if io.is_debug():
                    io.write_line("Deactivating the PyPI repository")
            else:
                pool.add_repository(
                    cls.create_package_source(
                        {"name": "pypi"}, config, disable_cache=disable_cache
                    ),
                    priority=Priority.PRIMARY,
                )

        if not pool.repositories:
            raise PoetryError(
                "At least one source must not be configured as 'explicit'."
            )

        return pool

    @classmethod
    def create_package_source(
        cls, source: dict[str, str], config: Config, disable_cache: bool = False
    ) -> HTTPRepository:
        from poetry.repositories.exceptions import InvalidSourceError
        from poetry.repositories.legacy_repository import LegacyRepository
        from poetry.repositories.pypi_repository import PyPiRepository
        from poetry.repositories.single_page_repository import SinglePageRepository

        try:
            name = source["name"]
        except KeyError:
            raise InvalidSourceError("Missing [name] in source.")

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