# NousResearch/hermes-agent · Guard IMAP empty search results against IndexError ## Open now - Nothing open on GitHub. Multiple related issues and pull requests addressing an IndexError that occurs when IMAP search returns empty data. One broader fix batch also touches PortAudio, SafeWriter, thread lock, and prefill alongside this IMAP guard. ## TL;DR - 6 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 4 PR(s) closed without merging. - A fix was merged to main in PR #2466. Verify it addresses your case. - **Recommended:** read PR #2466 (and any competing PRs below) before filing. Confirm the merged change covers your symptom. ## Maintainer resolution verdict - Internal-tracker verdict over this cluster's issue members: `unresolved`. This is distinct from the fix status above. Weigh it yourself. ## How this cluster was grouped - Link evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference. - Pairwise link density `0.33`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked. ## Closed / duplicate issues - #2137: fix(email): IndexError when IMAP search returns empty data list ## Prior & competing PRs - **#2249: fix(email): guard against empty IMAP search data to prevent IndexError**. closed without merge · fix tier `suggested` - maintainer direction: category `uncategorized`; implication `needs_llm` - _suggested-tier fix detail withheld; re-request with `?tier=all` to include it._ - **#2466: fix: batch of 5 small contributor fixes — PortAudio, SafeWriter, IMAP, thread lock, prefill**. merged to main · fix tier `verified` - maintainer direction: category `merged`; implication `superseded` - files: `gateway/platforms/email.py`, `hermes_state.py`, `run_agent.py`, `tools/voice_mode.py` - fix hunks: - `gateway/platforms/email.py` ```diff @@ -230,7 +230,7 @@ async def connect(self) -> bool: # Mark all existing messages as seen so we only process new ones imap.select("INBOX") status, data = imap.uid("search", None, "ALL") - if status == "OK" and data[0]: + if status == "OK" and data and data[0]: for uid in data[0].split(): self._seen_uids.add(uid) imap.logout() ``` ```diff @@ -295,7 +295,7 @@ def _fetch_new_messages(self) -> List[Dict[str, Any]]: imap.select("INBOX") status, data = imap.uid("search", None, "UNSEEN") - if status != "OK" or not data[0]: + if status != "OK" or not data or not data[0]: imap.logout() return results ``` - `hermes_state.py` ```diff @@ -855,23 +855,25 @@ def search_sessions( def session_count(self, source: str = None) -> int: """Count sessions, optionally filtered by source.""" - if source: - cursor = self._conn.execute( - "SELECT COUNT(*) FROM sessions WHERE source = ?", (source,) - ) - else: - cursor = self._conn.execute("SELECT COUNT(*) FROM sessions") - return cursor.fetchone()[0] + with self._lock: + if source: + cursor = self._conn.execute( + "SELECT COUNT(*) FROM sessions WHERE source = ?", (source,) + ) + else: + cursor = self._conn.execute("SELECT COUNT(*) FROM sessions") + return cursor.fetchone()[0] def message_count(self, session_id: str = None) -> int: """Count messages, optionally for a specific session.""" - if session_id: - cursor = self._conn.execute( - "SELECT COUNT(*) FROM messages WHERE session_id = ?", (session_id,) - ) - else: - cursor = self._conn.execute("SELECT COUNT(*) FROM messages") - return cursor.fetchone()[0] + with self._lock: + if session_id: + cursor = self._conn.execute( + "SELECT COUNT(*) FROM messages WHERE session_id = ?", (session_id,) + ) + else: + cursor = self._conn.execute("SELECT COUNT(*) FROM messages") + return cursor.fetchone()[0] # ========================================================================= # Export and cleanup ``` - `run_agent.py` ```diff @@ -108,7 +108,7 @@ class _SafeWriter: - """Transparent stdio wrapper that catches OSError from broken pipes. + """Transparent stdio wrapper that catches OSError/ValueError from broken pipes. When hermes-agent runs as a systemd service, Docker container, or headless daemon, the stdout/stderr pipe can become unavailable (idle timeout, buffer ``` ```diff @@ -117,8 +117,13 @@ class _SafeWriter: run_conversation() — especially via double-fault when an except handler also tries to print. + Additionally, when subagents run in ThreadPoolExecutor threads, the shared + stdout handle can close between thread teardown and cleanup, raising + ``ValueError: I/O operation on closed file`` instead of OSError. + This wrapper delegates all writes to the underlying stream and silently - catches OSError. It is transparent when the wrapped stream is healthy. + catches both OSError and ValueError. It is transparent when the wrapped + stream is healthy. """ __slots__ = ("_inner",) ``` ```diff @@ -129,13 +134,13 @@ def __init__(self, inner): def write(self, data): try: return self._inner.write(data) - except OSError: + except (OSError, ValueError): return len(data) if isinstance(data, str) else 0 def flush(self): try: self._inner.flush() - except OSError: + except (OSError, ValueError): pass def fileno(self): ``` ```diff @@ -144,7 +149,7 @@ def fileno(self): def isatty(self): try: return self._inner.isatty() - except OSError: + except (OSError, ValueError): return False def __getattr__(self, name): ``` ```diff @@ -2438,7 +2443,18 @@ def _sanitize_api_messages(messages: List[Dict[str, Any]]) -> List[Dict[str, Any "Pre-call sanitizer: added %d stub tool result(s)", len(missing_results), ) - + # 3. Strip trailing empty assistant messages to prevent prefill rejection. + # These can leak from Responses API reasoning-only turns (Codex/MiniMax) + # where an empty assistant message is required by the Responses API but + # must NOT be sent to Chat Completions or Anthropic Messages API providers. + while ( + messages + and messages[-1].get("role") == "assistant" + and not (messages[-1].get("content") or "").strip() + and not messages[-1].get("tool_calls") + ): + logger.debug("Pre-call sanitizer: removed trailing empty assistant message") + messages = messages[:-1] return messages @staticmethod ``` - `tools/voice_mode.py` ```diff @@ -81,8 +81,15 @@ def detect_audio_environment() -> dict: warnings.append("No audio input/output devices detected") except Exception: warnings.append("Audio subsystem error (PortAudio cannot query devices)") - except (ImportError, OSError): + except ImportError: warnings.append("Audio libraries not installed (pip install sounddevice numpy)") + except OSError: + warnings.append( + "PortAudio system library not found -- install it first:\n" + " Linux: sudo apt-get install libportaudio2\n" + " macOS: brew install portaudio\n" + "Then retry /voice on." + ) return { "available": len(warnings) == 0, ``` - **#2141: fix(email): guard against empty IMAP search data before indexing**. closed without merge - maintainer direction: category `duplicate_of`; implication `duplicate` - **#2144: fix(email): guard IMAP empty search results to prevent IndexError (#2137)**. closed without merge - maintainer direction: category `duplicate_of`; implication `duplicate` - **#2289: fix(email): guard against IndexError when IMAP search returns empty list**. closed without merge - maintainer direction: category `merged_via`; implication `superseded`; refs `#2466` ## Fix status - Merged to main in PR #2466 (cited above). No release data is tracked. Verify downstream. - Fix last verified (merged) `2026-03-22`. This confirmation is old and may be out of date (a revert/reopen would not have invalidated it here); re-verify. - Subsystem: `agent`