Background tasks on non-local backends (SSH/Docker/Modal/Daytona/Singularity)
go through `ProcessRegistry.spawn_via_env`, which builds a hand-crafted,
shell-safe wrapper:
mkdir -p T && ( nohup bash -lc CMD > LOG 2>&1; rc=$?; ... ) & echo $! > PID && cat PID
`BaseEnvironment.execute()` unconditionally ran `_rewrite_compound_background`
on every command, including this wrapper. The rewrite (meant to defuse the
`A && B &` subshell-wait trap for user commands) turns `( ... ) & echo $!` into
`{ ( ... ) & } echo $!` — note `} echo` with no separator, which is a bash
syntax error. The wrapper then never produces a PID, the redirected output file
is never created, and the agent sees an immediate exit code -1. This breaks
*every* background launch on a non-local backend (e.g. a simple
count-and-redirect script over SSH), not just edge cases.
Fix:
- Add `rewrite_compound_background: bool = True` to `BaseEnvironment.execute()`
(and the `BaseModalExecutionEnvironment` override, which accepts and ignores
it). Default preserves existing behavior; the user foreground terminal path
still rewrites.
- `spawn_via_env` passes `rewrite_compound_background=False` so its already
shell-safe wrapper is left intact.
- Treat a wrapper that produces no PID as a failed launch (mark the session
exited with a real exit code instead of exposing a fake running session), and
don't register/checkpoint a session that never started.
Verified empirically: with the rewrite skipped, the wrapper is valid bash,
launches the process, captures the PID, and writes the log/pid/exit files; the
old rewritten form fails `bash -n` with a syntax error.
Based on #33756 by @CharZhou (extracted from a multi-feature branch; the
unrelated image_gen / docker-media changes are not included here).
Co-authored-by: CharZhou <17255546+CharZhou@users.noreply.github.com>
- Extract duplicated activity-callback polling into shared
touch_activity_if_due() helper in tools/environments/base.py
- Use helper from both base.py _wait_for_process and
code_execution_tool.py local polling loop (DRY)
- Add test assertion that timeout output field contains the
timeout message and emoji (#10807)
- Add stream_consumer test for tool-boundary fallback scenario
where continuation is empty but final_text differs from
visible prefix (#10807)
Multiple gaps in activity tracking could cause the gateway's inactivity
timeout to fire while the agent is actively working:
1. Streaming wait loop had no periodic heartbeat — the outer thread only
touched activity when the stale-stream detector fired (180-300s), and
for local providers (Ollama) the stale timeout was infinity, meaning
zero heartbeats. Now touches activity every 30s.
2. Concurrent tool execution never set the activity callback on worker
threads (threading.local invisible across threads) and never set
_current_tool. Workers now set the callback, and the concurrent wait
uses a polling loop with 30s heartbeats.
3. Modal backend's execute() override had its own polling loop without
any activity callback. Now matches _wait_for_process cadence (10s).
