python-poetry/poetry · error · ValueError

The following packages were not found: {', '.join(sorted(not

Error message

The following packages were not found: {', '.join(sorted(not_found))}

What it means

ValueError from `poetry remove` (remove.py:162-166) when one or more named packages were not located in any dependency section (`[tool.poetry.dependencies]`, `[tool.poetry.group.*.dependencies]`, or `[dependency-groups]`). `removed` accumulates found packages; the set difference yields the missing ones.

Source

Thrown at src/poetry/console/commands/remove.py:164

                        packages=packages,
                        standard_section=groups_content[group],
                        poetry_section={},
                        group_name=group,
                    )
                )
                if not groups_content[group]:
                    del groups_content[group]
            if group not in groups_content and group not in poetry_groups_content:
                self._remove_references_to_group(group, content)

        if "group" in poetry_content and not poetry_content["group"]:
            del poetry_content["group"]
        if "dependency-groups" in content and not content["dependency-groups"]:
            del content["dependency-groups"]

        not_found = set(packages).difference(removed)
        if not_found:
            raise ValueError(
                "The following packages were not found: " + ", ".join(sorted(not_found))
            )

        # Refresh the locker
        self.poetry.locker.set_pyproject_data(content)
        self.installer.set_locker(self.poetry.locker)
        self.installer.set_package(self.poetry.package)
        self.installer.dry_run(self.option("dry-run", False))
        self.installer.verbose(self.io.is_verbose())
        self.installer.update(True)
        self.installer.execute_operations(not self.option("lock"))
        self.installer.whitelist(removed)

        status = self.installer.run()

        if not self.option("dry-run") and status == 0:
            self.poetry.file.write(content)

View on GitHub (pinned to 92b74dcfe3)

Solutions

1. Confirm the exact name with `poetry show` or by inspecting pyproject.toml.
2. Use the canonical (normalized) name as declared.
3. If it is a transitive dependency, remove the parent that requires it instead.

Example fix

# before
poetry remove requets
# after
poetry remove requests

from poetry.factory import Factory
poetry = Factory().create_poetry()
declared = {d.name for d in poetry.package.all_requires}
requested = {"requests"}
missing = requested - declared
if missing:
    raise SystemExit(f"not declared: {sorted(missing)}")

def is_declared_dependency(poetry, name: str) -> bool:
    from packaging.utils import canonicalize_name
    target = canonicalize_name(name)
    return any(canonicalize_name(d.name) == target
               for d in poetry.package.all_requires)

When it happens

Trigger: Running `poetry remove foes` when only `requests` is declared; removing a transitive dependency that is not a direct requirement; case mismatches.

Common situations: Typos; package already removed; package present only in the lock file (transitive) — `remove` only operates on direct requirements.

Related errors

• Invalid package definition.
• Setting {self.argument('key')} does not exist
• You can only pass one value.
• "{value}" is an invalid value for {key}
• Group(s) not found: {', '.join(message_parts)}

AI-assisted analysis of python-poetry/poetry@92b74dcfe3 (2026-08-04). Data as JSON: /data/errors/2bfc7500ee604499.json. Report an issue: GitHub.