Hey, thanks for the report. The level of detail, repro steps, and log analysis are above average and really helpful. A few notes:
About splitting into threads. The report mixes three different bugs with different root causes (McpProcess IPC, SQLite disk writes, Remote-SSH prompt loop). To track each one correctly and link it to the right internal tickets, it works best if each bug is in its own thread. Can you split it into three separate posts? Keep this one as the summary / Bug #1 (McpProcess), and create new ones for Bug #2 and Bug #3.
About cursor.agent.legacyMcpMode. That setting doesn’t exist in the Cursor codebase. What you see as “it works after adding it” is likely just the automatic fallback to the legacy in-window MCP, which already happens after the retry budget is exhausted (~90s). The setting itself does nothing. Where did that name come from, logs or an AI suggestion? If it came from an AI suggestion, that’s a hallucination.
Real workaround right now if you want to skip the 90s retry loop: there isn’t one (the fallback happens automatically). If you can confirm that the ipcReady timeout goes away in 3.4.17 after some specific environment change (for example disabling security tooling, antivirus, or granting specific macOS permissions), that would really help with diagnosis.
About Bug #2 and Bug #3 (after you split them into threads), both fall into known bug classes:
- Excessive SQLite writes: tied to unbounded growth of
state.vscdb(cursorDiskKV), we’re already tracking this. - Remote-SSH prompt loop: the same ID mismatch pattern as Dev Containers / WSL, see Extension 'Dev Containers' is required: Agents Window - broken and Dev container remotes don't work with Glass. Known issue in Glass remote restoration.
For Bug #1, a Console.app crash report for McpProcess would be useful (or Diagnostics → User Reports filtered by mcpProcess). If you can attach that, it usually shows the exit code, signal, or the library where the process dies. SIGTRAP when running the binary directly is also interesting, if you can share the full terminal output from running it, we can take a look.
I can’t share an ETA for fixes.