Troubleshooting

fb uses distinct exit codes so scripts can tell apart "private", "not found", and a real failure. When something goes wrong, the exit code is the first thing to check.

Exit codes

Code	Meaning
0	Success
1	Generic error
2	Usage error (bad flags or arguments)
3	Content not found or unavailable anonymously
4	Login wall: the content is not public
5	Rate limited
6	Network error

"Login wall" (exit 4)

Facebook only puts public content on the crawler surface fb reads. Exit 4 means the target is behind a login wall: a private profile or group, or a Page that is not visible to anonymous visitors. There is no cookie to set; the content is simply not reachable this way. Confirm fb is reading anonymously and check the URL it fetched:

fb whoami
fb page nasa -vv

See how fb reads Facebook for what the crawler surface exposes and what stays private.

"Content unavailable" (exit 3)

Facebook returned an error or "not available" page. The specific item is gone, private, or region-blocked. Add -v to see the URL fetched and confirm it is the one you meant.

Rate limited (exit 5)

Facebook is throttling the crawler. fb already retries with backoff; if it still exits 5, slow down: raise --rate, lower -j/--workers, and avoid running several large crawls at once. A crawler that is pushed too hard can be temporarily blocked.

Nothing comes back, but exit 0

A feed or list legitimately had no items (an account with no public posts, a Page with no events). That is a clean, empty result, not an error. Add -v to see the URLs fetched and confirm fb reached the page you expected.

Seeing what fb does

-v (repeatable) logs request activity to stderr; -vv logs every URL and cache hit. --raw prints the upstream HTML untouched so you can inspect exactly what Facebook returned:

fb page nasa -vv
fb page nasa --raw | head

Stale cache

If a command returns data you know is out of date, the cache is serving an old response. Bypass it for one run with --no-cache, or clear it entirely:

fb page nasa --posts --no-cache
fb cache clear