cancel_by_session() only cancelled asyncio tasks, leaving child
processes from exec sessions orphaned. Since each SubagentManager
now owns a dedicated ExecSessionManager, terminate those sessions
by owner_session_key after cancelling tasks.
Add ExecSessionManager.terminate_by_owner() to kill all sessions
for a given owner, and call it from cancel_by_session().
Maintainer edit: keep a top-level trailing '&' in the segment being matched so background execution cannot be checked as if the ampersand were absent. Redirection forms like 2>&1 and &> remain untouched.
Maintainer edit: keep the single-ampersand guard behavior, but fold the redirect exceptions into one condition instead of carrying temporary previous/next character variables.
Maintainer edit: single '&' backgrounds the preceding command and starts another top-level shell segment, so allowPatterns must split it the same way as ';', '|', '&&', and '||'. Keep fd redirections such as 2>&1 and &> intact.
Fixes chengyongru's review concern: re.search is more permissive
than the original re.fullmatch behavior for single-segment commands.
Using re.fullmatch per segment preserves backward compatibility while
still fixing the chained-command bypass.
Guard against shell-chain bypass where an attacker appends '&& malicious'
after an allowlisted prefix. The allowlist check now splits the command
on top-level chaining operators (&&, ||, ;, |) and requires every segment
to match at least one allowPattern independently.
Fixes#4521
When an MCP server (e.g. stdio browser-agent subprocess) does not
terminate within the AsyncExitStack.aclose() timeout, asyncio raises
CancelledError. The existing exception handler only caught RuntimeError
and BaseExceptionGroup, so CancelledError escaped the except block and
crashed nanobot with exit code 1 on every shutdown.
Add asyncio.CancelledError to the caught exception tuple so the error
is logged at debug level and shutdown completes cleanly.
Stack trace from the crash:
Traceback (most recent call last):
File ".../nanobot/agent/loop.py", line 1194, in close_mcp
await stack.aclose()
asyncio.exceptions.CancelledError
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File ".../asyncio/__main__.py", line ?, in <module>
File ".../nanobot/agent/loop.py", line ?, in close_mcp
...
RuntimeError: ... (or BaseExceptionGroup) not caught
SystemExit: 1
Replace the legacy long-goal skill contract with command-scoped goal tools and runtime guidance. Keep goal state durable across continuations while restricting create and replace mutations to explicit user /goal turns.
Skip process.kill() when returncode is already set so generic exception
handlers after a successful communicate() cannot raise ProcessLookupError.
Suppress race kill failures and still run the safety-net reap.
Add unit and integration coverage for owned-PID reaping on normal exit,
timeout, exception, and exec-session kill/poll paths.
Windows CI runs Unix-path unit tests by patching _IS_WINDOWS=False while
still on win32, where os.WNOHANG/os.waitpid do not exist. Use capability
checks so reaping is a no-op on platforms without waitpid rather than
trusting the (mockable) platform flag.
The previous fix (dbcc7cb5) only added os.waitpid() to _kill_process(),
covering the timeout/cancel path of one-shot exec. Zombies continued to
accumulate because several other exit paths never reaped children:
- _ExecSession.kill(): sent SIGKILL + process.wait(5s) but had no
os.waitpid() fallback if the wait timed out
- ExecTool.execute() generic exception handler: leaked the subprocess
if communicate() raised an unexpected error
- Normal completion paths: relied entirely on asyncio's child-watcher,
which can miss exits inside Docker containers (pidfd/SIGCHLD gaps)
Changes:
- Extract _reap_pid() helper for consistent, safe os.waitpid(WNOHANG)
- Add _reap_pid() fallback to _ExecSession.kill() via try/finally
- Add _reap_pid() safety-net after normal process exit in both
ExecTool.execute() and _ExecSession.poll()
- Kill + reap subprocess in the generic except Exception handler
- Add periodic zombie reaper background task (every 30s) in the
gateway as a last line of defense
chengyongru
Xubin Ren
amplifierplus
yu-xin-c
AxelRay
KDB
chengyongru
yorkhellen
michaelxer
adabarbulescu
chengyongru
Brian Noah
flyzstu
Eric Yang
NOKIAO