docker install broken on linux: searxng 2026.5.31-7159b8aed fails with KeyError: 'default_doi_resolver'

[winklevos]

Prerequisites

• I searched open issues and discussions and did not find an existing report of this bug.
• This is not a security vulnerability. (Vulnerabilities go to GitHub Security Advisories — see SECURITY.md.)
• I am running the latest code from the dev branch (the default branch you get on clone, where fixes land first) and the bug still reproduces there. Please git pull the latest dev before filing.

Install Method

Docker (docker compose up)

Operating System

Linux

Steps to Reproduce

git clone https://github.com/odysseus-dev/odysseus.git
cd odysseus
cp .env.example .env
docker compose up -d --build

occurs on dev and main

Expected Behaviour

searxng completes

Actual Behaviour

searxng unhealthy KeyError: 'default_doi_resolver'

Logs / Screenshots

SearXNG 2026.5.31-7159b8aed

Updating certificates in /etc/ssl/certs...

0 added, 0 removed; done.

Running hooks in /etc/ca-certificates/update.d...

done.

[INFO] Starting granian (main PID: 1)

[INFO] Listening at: http://:::8080

[INFO] Spawning worker-1 with PID: 927

2026-08-15 04:02:44,956 WARNING:searx.botdetection.config: missing config file: /etc/searxng/limiter.toml

[INFO] Started worker-1

2026-08-15 04:02:49,204 ERROR:searx.botdetection: X-Forwarded-For nor X-Real-IP header is set!

2026-08-15 04:02:49,205 ERROR:searx.webapp: Exception on / [GET]

Traceback (most recent call last):

  File "/usr/local/searxng/.venv/lib/python3.14/site-packages/flask/app.py", line 1511, in wsgi_app

    response = self.full_dispatch_request()

  File "/usr/local/searxng/.venv/lib/python3.14/site-packages/flask/app.py", line 919, in full_dispatch_request

    rv = self.handle_user_exception(e)

  File "/usr/local/searxng/.venv/lib/python3.14/site-packages/flask/app.py", line 915, in full_dispatch_request

    rv = self.preprocess_request()

  File "/usr/local/searxng/.venv/lib/python3.14/site-packages/flask/app.py", line 1291, in preprocess_request

    rv = self.ensure_sync(before_func)()

  File "/usr/local/searxng/searx/webapp.py", line 466, in pre_request

    preferences = Preferences(themes, list(categories.keys()), engines, searx.plugins.STORAGE, client_pref)

  File "/usr/local/searxng/searx/preferences.py", line 461, in __init__

    [get_setting("default_doi_resolver")],

     ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^

  File "/usr/local/searxng/searx/__init__.py", line 97, in get_setting

    raise KeyError(name)

KeyError: 'default_doi_resolver'

Model / Backend (if relevant)

No response

Are you willing to submit a fix?

Yes — I can open a PR

Additional Information

Related previous issue #1414

[RaresKeY]

Confirmed this is an upgrade-path issue rather than a fresh-install regression: current dev is healthy with a fresh SearXNG config, while the HTTP 500 / missing default_doi_resolver reproduces when a retained nonempty legacy/custom /etc/searxng/settings.yml lacks top-level use_default_settings: true. Preservation-safe upgrade hardening is tracked in #6054 and implemented in #6055. Leaving this report open for inspection and follow-up.