Troubleshooting terminal-tools

Recipes for surprising results. Match the symptom to the section.

Empty stdout despite the command "should have" produced output

Possible causes:

1. Output went to stderr instead. Check stderr in the envelope (or use merge_stderr=True for jobs).
2. Output was fully truncated because max_output_kb is too small. Check stdout_truncated_bytes > 0. Bump max_output_kb or paginate via output_handle.
3. Command produced no output (correct, just unexpected — silent flags, no matches).
4. Pipeline issue: the last stage of a pipe ran but stdout went elsewhere (> /dev/null, redirected via 2>&1).
5. Process is buffering its output and didn't flush before exit. Add stdbuf -oL (line-buffered) or unbuffer to 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, then signal_term the 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 / rg exit 1 when no matches found
• find exit 1 when some directories were unreadable (typical on /proc, etc.)
• diff exit 1 when files differ
• test / [ 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.