What causes "Problem while attempting to access data file '{data_file_path}'." in sherlock-project/sherlock?

Verify existence from the same shell/CWD you run sherlock in: `ls -l `; if missing, correct the path or copy the file there.

sherlock-project/sherlock · error · FileNotFoundError

Problem while attempting to access data file '{data_file_pat

Error message

Problem while attempting to access data file '{data_file_path}'.

What it means

When data_file_path does not start with 'http', sites.py treats it as a filesystem path; open() raising FileNotFoundError is caught and re-raised as FileNotFoundError with this clearer message. It means exactly what it says: no regular file exists at that path relative to the current working directory of the sherlock process.

Source

Thrown at sherlock_project/sites.py:156

                site_data = response.json()
            except Exception as error:
                raise ValueError(
                    f"Problem parsing json contents at '{data_file_path}':  {error}."
                )

        else:
            # Reference is to a file.
            try:
                with open(data_file_path, "r", encoding="utf-8") as file:
                    try:
                        site_data = json.load(file)
                    except Exception as error:
                        raise ValueError(
                            f"Problem parsing json contents at '{data_file_path}':  {error}."
                        )

            except FileNotFoundError:
                raise FileNotFoundError(f"Problem while attempting to access "
                                        f"data file '{data_file_path}'."
                                        )

        site_data.pop('$schema', None)

        if honor_exclusions:
            try:
                response = requests.get(url=EXCLUSIONS_URL, timeout=10)
                if response.status_code == 200:
                    exclusions = response.text.splitlines()
                    exclusions = [exclusion.strip() for exclusion in exclusions]

                    for site in do_not_exclude:
                        if site in exclusions:
                            exclusions.remove(site)

                    for exclusion in exclusions:
                        try:

View on GitHub (pinned to 9100f9d40a)

Solutions

Verify existence from the same shell/CWD you run sherlock in: `ls -l <path>`; if missing, correct the path or copy the file there.
Use an absolute path to remove CWD ambiguity: `sherlock --site /home/me/sherlock/data.json username`.
In Docker/CI, confirm the manifest is mounted/copied into the container and reference the in-container absolute path.
Quote paths with spaces and check exact casing on Linux.

Example fix

# before
sherlock --site data.json john_doe   # run from ~/, file lives in ~/sherlock/

# after
sherlock --site ~/sherlock/data.json john_doe  # or an absolute path

Defensive patterns

Strategy: validation

Validate before calling

import os

def manifest_path_exists(path: str) -> bool:
    """Resolve like sherlock does (relative to CWD) and confirm a readable file."""
    resolved = os.path.abspath(path)  # sherlock resolves non-http paths against CWD
    return os.path.isfile(resolved) and os.access(resolved, os.R_OK)

Try / catch

from pathlib import Path
from sherlock_project.sites import SitesInformation

manifest = Path("data.json").expanduser().resolve()
if not manifest.is_file():
    raise SystemExit(f"manifest not found at {manifest}; pass --site /abs/path/data.json")
sites = SitesInformation(data_file_path=str(manifest))

Prevention

Always pass an absolute path (or resolve with Path(...).resolve()) — sherlock resolves relative manifest paths against the process CWD, not the script location.
In containers/services, verify the manifest is mounted at the expected absolute path before start.
Quote paths containing spaces and double-check casing on case-sensitive filesystems.
Note that a directory named data.json also triggers open() failure; ensure the path points at a regular file.

When it happens

Trigger: `sherlock --site data.json user` run from a directory that does not contain data.json (relative paths are resolved against CWD, not the script location); a typo'd filename; a path with a missing directory component; running sherlock as a systemd service/Docker container whose WORKDIR differs from where the manifest was copied; shell expansion swallowing characters (spaces, ~ not expanded inside quotes).

Common situations: Assuming the path is relative to the sherlock package or to the user's home rather than the current directory; invoking sherlock from another machine/container where the file was never mounted; paths containing unquoted spaces; case-sensitive filesystems after copying files from macOS/Windows.

Related errors

AI-assisted analysis of sherlock-project/sherlock@9100f9d40a (2026-08-14). Data as JSON: /api/errors/ef9fcbe5ab4571d2. Report an issue: GitHub.