pytest-dev/pytest · error · UsageError

not found: {arg} (no match in any of {collectors!r})

Error message

not found: {arg}
(no match in any of {collectors!r})

What it means

main.py:862 reports 'not found: {arg}\n(no match in any of {collectors!r})' during collection when a command-line argument resolved to one or more collector objects but none of them produced matching items for the given selection. The argument was located as a collector but the '::part' or pattern did not match any test inside. This is a UsageError raised after _notfound entries accumulate.

Source

Thrown at src/_pytest/main.py:862

                initialpaths_with_parents.append(collection_argument.path)
                initialpaths_with_parents.extend(collection_argument.path.parents)
            self._initialpaths = frozenset(initialpaths)
            self._initialpaths_with_parents = frozenset(initialpaths_with_parents)

            rep = collect_one_node(self)
            self.ihook.pytest_collectreport(report=rep)
            self.trace.root.indent -= 1
            if self._notfound:
                errors = []
                for arg, collectors in self._notfound:
                    if collectors:
                        errors.append(
                            f"not found: {arg}\n(no match in any of {collectors!r})"
                        )
                    else:
                        errors.append(f"found no collectors for {arg}")

                raise UsageError(*errors)

            if not genitems:
                items = rep.result
            else:
                if rep.passed:
                    for node in rep.result:
                        self.items.extend(self.genitems(node))

            self.config.pluginmanager.check_pending()
            hook.pytest_collection_modifyitems(
                session=self, config=self.config, items=items
            )
        finally:
            self._notfound = []
            self._initial_parts = []
            self._collection_cache = {}
            hook.pytest_collection_finish(session=self)

View on GitHub (pinned to 0d6fbdeffa)

Solutions

1. Run 'pytest path/to/test_file.py --collect-only' to list the exact valid nodeids.
2. Correct the '::part' spelling in the command to match an existing test/class.
3. If the test was removed, update CI configs and scripts referencing it.
4. Use --co -q to get machine-readable nodeids for copy-paste.

Example fix

// before
pytest tests/test_user.py::TestUser::test_delet  # typo
// after
pytest tests/test_user.py::TestUser::test_delete

# Before running, list valid nodeids and verify the target exists
import subprocess, sys
out = subprocess.run([sys.executable,'-m','pytest','--collect-only','-q', path],
                    capture_output=True, text=True).stdout
nodeids = {l.strip() for l in out.splitlines() if '::' in l}
assert target in nodeids, f'{target!r} not in collected nodeids'

When it happens

Trigger: Running 'pytest path/to/test_file.py::TestClass::test_wrong_name' where the method does not exist; selecting a class/function name that has a typo; using a nodeid whose '::' parts reference an absent nested item.

Common situations: Renaming a test and forgetting to update CI invocation strings; stale nodeids copied from old runs; selecting parametrized IDs that no longer exist; wrong class name in a deselect/keyword context.

Related errors

• found no collectors for {arg}
• package argument cannot contain :: selection parts: {arg}
• directory argument cannot contain :: selection parts: {arg}
• path cannot contain [] parametrization: {arg}
• file or directory not found: {arg}

AI-assisted analysis of pytest-dev/pytest@0d6fbdeffa (2026-08-11). Data as JSON: /api/errors/5117955129ee94d6. Report an issue: GitHub.