Troubleshooting terminal-tools
Recipes for surprising results. Match the symptom to the section.
Empty stdout despite the command "should have" produced output
Possible causes:
- Output went to stderr instead. Check
stderrin the envelope (or usemerge_stderr=Truefor jobs). - Output was fully truncated because
max_output_kbis too small. Checkstdout_truncated_bytes > 0. Bumpmax_output_kbor paginate viaoutput_handle. - Command produced no output (correct, just unexpected —
silentflags, no matches). - Pipeline issue: the last stage of a pipe ran but stdout went elsewhere (
> /dev/null, redirected via2>&1). - Process is buffering its output and didn't flush before exit. Add
stdbuf -oL(line-buffered) orunbufferto the command.
exit_code: null
| Cause | Other field |
|---|---|
| Auto-backgrounded | auto_backgrounded: true, job_id: <X> |
| Hard timeout, process killed | timed_out: true |
| Pre-spawn failure (command not found) | error: ... set, pid: null |
Still running (in terminal_job_logs) | status: "running" |
output_handle returned expired: true
5-minute TTL. Either (a) you waited too long, or (b) the store evicted it under memory pressure (64 MB total cap, LRU eviction). Re-run the command.
To reduce risk: paginate the handle as soon as you receive it, or use terminal_job_* for huge outputs (4 MB ring buffer with offsets — no expiry).
"too many jobs" / JobLimitExceeded
TERMINAL_TOOLS_MAX_JOBS (default 32) hit. Either:
- Wait for jobs to exit (poll with
terminal_job_logs(wait_until_exit=True)) - Kill old jobs:
terminal_job_manage(action="list")to see what's running, thensignal_termthe abandoned ones - Raise the cap via env (rare)
"session busy"
A terminal_pty_run was issued while another _run is in flight on the same session. PTY sessions are single-threaded conversations. Wait for the prior call to return, or open a second session.
"PTY cap reached"
TERMINAL_TOOLS_MAX_PTY (default 8) hit. Close idle sessions (terminal_pty_close). Idle reaping is lazy; force it by opening — no, actually, opening throws when the cap is hit. Just close manually.
warning is set, the command worked
Informational only. The pattern matched (e.g. rm -rf literally appears, or git push --force was used). The command ran. The warning is your "did I mean to do that?" prompt — verify the side effect was intended before continuing.
semantic_status: "ok" but exit_code: 1
Working as designed. Some commands use exit 1 for legitimate non-error states:
grep/rgexit 1 when no matches foundfindexit 1 when some directories were unreadable (typical on/proc, etc.)diffexit 1 when files differtest/[exit 1 when condition is false
The semantic_message field explains. Trust semantic_status, not raw exit_code.
semantic_status: "error" but exit_code: 0
Shouldn't happen. If it does, file a bug.
truncated_bytes_dropped > 0 in terminal_job_logs
Your since_offset was older than the ring buffer's floor — bytes evicted before you could read them. Either:
- Poll faster (lower latency between calls)
- Use
merge_stderr=True(single 4 MB ring instead of 4 MB × 2) - Accept the gap and move forward from
next_offset
terminal_pty_open succeeds but the first _run times out
The session may not have produced its first prompt sentinel within the 2-second startup window. Try:
- A
terminal_pty_run(sid, read_only=True, timeout_sec=2)to drain whatever's accumulated - A noop command (
terminal_pty_run(sid, command="true")) to force a prompt cycle
Could also indicate the bash process died at startup — terminal_pty_run(sid, ...) would then return "session has exited".
shell="/bin/zsh" returned an error
By design. terminal-tools is bash-only on POSIX. Use shell=True (default /bin/bash) or omit shell= to exec directly.
A command in shell=True is interpreted differently than expected
Bash, not zsh, semantics. **/* doesn't recurse without shopt -s globstar; =cmd expansion doesn't work; arrays use arr[idx] not ${arr[idx]} differently than zsh. When in doubt, the foundational skill's "bash, not zsh" section is the canonical statement.
