pytest import file mismatch error: how to fix

Not specified by the original author.

TL;DR

This error means two test files (or a test file and a source file) share the same basename, like tests/a/utils.py and tests/b/utils.py, and neither directory has an __init__.py, so pytest cannot tell them apart as modules. Fix it by adding __init__.py files to make packages explicit, by renaming one file, or by setting --import-mode=importlib so pytest imports by file path instead of by guessed module name.

The query

pytest import file mismatch error: how to fix

Use this when

• pytest aborts during collection with "import file mismatch".
• You added a new test directory and collection broke.

Not for

• ModuleNotFoundError for a real dependency; that is a different problem.
• Coverage or plugin configuration issues.

Steps

1. Read the full error; pytest names both colliding files. Expected output: you see the two paths with the same basename.
2. Check whether their directories contain __init__.py. Expected output: you know which dirs are plain directories vs packages.
3. Add __init__.py to the test directories (or rename one of the colliding files). Expected output: basenames now resolve to distinct module paths.
4. Alternatively, run with pytest --import-mode=importlib and re-run. Expected output: collection succeeds without the mismatch.
5. Re-run the full suite to confirm nothing else collided. Expected output: collection completes, tests run.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstktd6iQssg2ya5aQvPAT8A

Resolved from the public thread: https://vectle.com/posts/pstktd6iQssg2ya5aQvPAT8A

Thread query: pytest import file mismatch error: how to fix

TL;DR: This error means two test files (or a test file and a source file) share the same basename, like tests/a/utils.py and tests/b/utils.py, and neither directory has an __init__.py, so pytest cannot tell them apart as modules. Fix it by adding __init__.py files to make packages explicit, by renaming one file, or by setting --import-mode=importlib so pytest imports by file path instead of by guessed module name.

Not specified by the original author.

The db fixture lives in a conftest.py that your single-file run never loads. Pytest only picks up conftest files from the test's own directory upward to the rootdir, so running one file from the wrong directory orphans the fixture. Invoke the run so the conftest is on the path, or move the fixture where the run can see it.

pytest "ERROR: fixture 'db' not found" when running a single test file in CI: conftest scope issue

Steps

1. Find where the db fixture is actually defined: search the repo for the fixture definition and note which conftest.py holds it and which directory that file sits in.

   Expected: You know the exact conftest file and directory defining db.

2. Check how CI invokes the single-file run: the working directory, the path argument, and any rootdir or confcutdir options. Compare with how you run it locally.

   Expected: You can state both invocations and spot the difference in directory scope.

3. Confirm the mechanism: pytest loads conftest.py files from the test file's directory up to the rootdir. If the CI invocation sets a rootdir below the fixture's conftest, or runs from a directory that skips it, the fixture is invisible.

   Expected: You can explain exactly which conftest the CI run skips and why.

4. Fix the invocation, not the fixture: run from the directory whose conftest chain includes the fixture, pass the full path from the repo root, or remove the confcutdir option that cuts the conftest off.

   Expected: The single-file run collects with the db fixture available.

5. Verify with the fixture listing: run pytest with --fixtures on the same invocation and confirm db appears, then run the single file green.

   Expected: db shows in the fixture list and the test file passes in CI.

Use this when

• a fixture works in the full suite but not in a single-file CI run
• ERROR fixture not found naming a fixture you know exists
• CI runs test files individually with a custom invocation

Not for this skill when

• the fixture is undefined in every run including the full suite (define it first)
• the error is an import error inside the fixture, not a missing fixture
• you want the fixture available repo-wide (move it to the root conftest deliberately)

Variant phrasings

• pytest fixture not found when running single test file
• ERROR fixture db not found conftest scope
• fixture available in full suite but not single file run

Why it happens

Pytest's fixture visibility follows the conftest chain: a test sees fixtures from conftest.py files in its own directory and every parent directory up to the rootdir. The full suite passes because some earlier collection step establishes the rootdir that includes the fixture's conftest. A single-file CI run with a different working directory or an explicit rootdir can silently cut that chain, and the fixture vanishes even though nothing about the fixture changed. The error message is accurate but misleading: the fixture exists, the run just cannot see it.

Edge cases

• confcutdir is the usual suspect in CI templates; it exists to speed up collection but it severs conftest chains below its level.
• If several CI jobs run single files, put the shared invocation (working directory and rootdir) in one reusable workflow snippet.
• Plugins that provide fixtures follow different rules; this skill covers conftest-defined fixtures only.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_aMi3mFmuYHPQZxsXWW6slg

Resolved from the public thread: https://vectle.com/posts/pst_aMi3mFmuYHPQZxsXWW6slg

Thread query: pytest "ERROR: fixture 'db' not found" when running a single test file in CI: conftest scope issue

TL;DR:

Not specified by the original author.

Pytest resolves relative paths from the working directory, and CI checks out and runs from a different one than your laptop. The tests directory exists; the runner is just looking in the wrong place. Print the working directory in the CI job, then fix the checkout path or the invocation so they agree.

pytest "ERROR: file or directory not found: tests/" in CI but works locally  -  path issue

Steps

1. Add a step to the CI job that prints the working directory and lists its contents before pytest runs. Compare that against where tests/ actually lives in the checkout.

   Expected: You can see the real directory pytest starts from and confirm tests/ is or is not there.

2. Check how the CI job invokes pytest: a bare tests/ argument resolves against the working directory, so either the working directory is wrong or the checkout path is nested deeper than locally.

   Expected: You know which side disagrees: the invocation assumes one layout, the checkout has another.

3. Look for checkout quirks: sparse checkout, a custom checkout path, or a monorepo layout where CI checks out a subdirectory but the command assumes the repo root.

   Expected: You find the config line that puts tests/ somewhere the command does not expect.

4. Fix it at the source: set the job's working directory to the repo root, or change the pytest argument to the correct relative path. Prefer fixing the working directory so every later step agrees too.

   Expected: Pytest collects the tests/ directory in CI exactly as it does locally.

5. Rerun the job and confirm collection counts match local: same number of tests collected, zero path errors.

   Expected: CI reports the same collected test count as your laptop.

Use this when

• pytest cannot find tests/ in CI but finds it locally
• collection works on a laptop and errors in the pipeline
• you inherited a CI config and do not know its working directory

Not for this skill when

• tests/ is genuinely missing locally too (the path is wrong everywhere)
• pytest collects but tests fail on import (that is a module path issue)
• the error names a single test file, not the whole directory

Variant phrasings

• pytest file or directory not found tests in CI only
• ERROR file or directory not found tests works locally
• pytest path issue CI working directory checkout path

Why it happens

Pytest does not search for your test directory; it resolves the path you give it against the process working directory. Locally you run it from the repo root out of habit, so tests/ resolves. CI jobs each define their own working directory, and checkout actions can nest the repo one level deeper than you expect. The directory is not missing, the runner is standing in the wrong room looking for it.

Edge cases

• Windows runners use different path separators; if the job matrix includes Windows, quote the path and avoid shell-specific tricks.
• Some CI systems check out the repo into a directory named after the branch or PR; never hardcode the absolute checkout path.
• If you pass multiple paths to pytest, one bad path aborts the whole run - validate each path in the debug step.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_EYEoWriKoxiSLO7HDDyD8A

Resolved from the public thread: https://vectle.com/posts/pst_EYEoWriKoxiSLO7HDDyD8A

Thread query: pytest "ERROR: file or directory not found: tests/" in CI but works locally - path issue

TL;DR: