fix(sandbox): pass no_change_timeout to exec_command to prevent 120s premature termination (#2685)

* fix(sandbox): pass no_change_timeout to exec_command to prevent 120s premature termination

  The agent_sandbox library's shell API defaults no_change_timeout to 120
  seconds. When AioSandbox.execute_command() called exec_command() without
  this parameter, commands producing no output for 120s would return with
  NO_CHANGE_TIMEOUT status even though the script was still running.

  Pass no_change_timeout=600 to all exec_command calls (matching the
  client-level HTTP timeout) so long-running commands are not cut short.

  Fixes #2668

* test(sandbox): add assertions for no_change_timeout in execute_command and list_dir

Agent-Logs-Url: https://github.com/bytedance/deer-flow/sessions/2f37bc72-0826-4443-a6ba-e5b78c22fb5a

Co-authored-by: WillemJiang <219644+WillemJiang@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

backend/packages/harness/deerflow/community/aio_sandbox/aio_sandbox.py

@@ -48,6 +48,12 @@ class AioSandbox(Sandbox):
             self._home_dir = context.home_dir
         return self._home_dir
 
+    # Default no_change_timeout for exec_command (seconds).  Matches the
+    # client-level timeout so that long-running commands which produce no
+    # output are not prematurely terminated by the sandbox's built-in 120 s
+    # default.
+    _DEFAULT_NO_CHANGE_TIMEOUT = 600
+
     def execute_command(self, command: str) -> str:
         """Execute a shell command in the sandbox.
 
@@ -66,13 +72,13 @@ class AioSandbox(Sandbox):
         """
         with self._lock:
             try:
-                result = self._client.shell.exec_command(command=command)
+                result = self._client.shell.exec_command(command=command, no_change_timeout=self._DEFAULT_NO_CHANGE_TIMEOUT)
                 output = result.data.output if result.data else ""
 
                 if output and _ERROR_OBSERVATION_SIGNATURE in output:
                     logger.warning("ErrorObservation detected in sandbox output, retrying with a fresh session")
                     fresh_id = str(uuid.uuid4())
-                    result = self._client.shell.exec_command(command=command, id=fresh_id)
+                    result = self._client.shell.exec_command(command=command, id=fresh_id, no_change_timeout=self._DEFAULT_NO_CHANGE_TIMEOUT)
                     output = result.data.output if result.data else ""
 
                 return output if output else "(no output)"
@@ -108,7 +114,7 @@ class AioSandbox(Sandbox):
         """
         with self._lock:
             try:
-                result = self._client.shell.exec_command(command=f"find {shlex.quote(path)} -maxdepth {max_depth} -type f -o -type d 2>/dev/null | head -500")
+                result = self._client.shell.exec_command(command=f"find {shlex.quote(path)} -maxdepth {max_depth} -type f -o -type d 2>/dev/null | head -500", no_change_timeout=self._DEFAULT_NO_CHANGE_TIMEOUT)
                 output = result.data.output if result.data else ""
                 if output:
                     return [line.strip() for line in output.strip().split("\n") if line.strip()]

backend/tests/test_aio_sandbox.py

@@ -133,6 +133,58 @@ class TestListDirSerialization:
         assert lock_was_held == [True], "list_dir must hold the lock during exec_command"
 
 
+class TestNoChangeTimeout:
+    """Verify that no_change_timeout is forwarded to every exec_command call."""
+
+    def test_execute_command_passes_no_change_timeout(self, sandbox):
+        """execute_command should pass no_change_timeout to exec_command."""
+        calls = []
+
+        def mock_exec(command, **kwargs):
+            calls.append(kwargs)
+            return SimpleNamespace(data=SimpleNamespace(output="ok"))
+
+        sandbox._client.shell.exec_command = mock_exec
+
+        sandbox.execute_command("echo hello")
+
+        assert len(calls) == 1
+        assert calls[0].get("no_change_timeout") == sandbox._DEFAULT_NO_CHANGE_TIMEOUT
+
+    def test_retry_passes_no_change_timeout(self, sandbox):
+        """The ErrorObservation retry path should also pass no_change_timeout."""
+        calls = []
+
+        def mock_exec(command, **kwargs):
+            calls.append(kwargs)
+            if len(calls) == 1:
+                return SimpleNamespace(data=SimpleNamespace(output="'ErrorObservation' object has no attribute 'exit_code'"))
+            return SimpleNamespace(data=SimpleNamespace(output="ok"))
+
+        sandbox._client.shell.exec_command = mock_exec
+
+        sandbox.execute_command("echo hello")
+
+        assert len(calls) == 2
+        assert calls[0].get("no_change_timeout") == sandbox._DEFAULT_NO_CHANGE_TIMEOUT
+        assert calls[1].get("no_change_timeout") == sandbox._DEFAULT_NO_CHANGE_TIMEOUT
+
+    def test_list_dir_passes_no_change_timeout(self, sandbox):
+        """list_dir should pass no_change_timeout to exec_command."""
+        calls = []
+
+        def mock_exec(command, **kwargs):
+            calls.append(kwargs)
+            return SimpleNamespace(data=SimpleNamespace(output="/a\n/b"))
+
+        sandbox._client.shell.exec_command = mock_exec
+
+        sandbox.list_dir("/test")
+
+        assert len(calls) == 1
+        assert calls[0].get("no_change_timeout") == sandbox._DEFAULT_NO_CHANGE_TIMEOUT
+
+
 class TestConcurrentFileWrites:
     """Verify file write paths do not lose concurrent updates."""