Cursor 3.7.27 Agent Broken on macOS 27 Beta (Darwin 27) cursor-retrieval spawn failed: Unknown system error -86

Support Bug Reports
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1

Describe the Bug

Machine:
Apple Silicon (arm64)

Issue:
Agent always times out.

Console Error:
[lansphere.cursor-retrieval] spawn
Unknown system error -86

Agent Error:
No first token received
Agent Execution Timed Out

Additional Info:
Running:
Cursor Helper (Plugin) --version

Results in:
zsh: trace trap
mach_vm_read invalid address (1)

Steps to Reproduce

  1. Install Cursor 3.7.27 on macOS 27 Beta (Darwin 27.0.0, Build 26A5353q).

  2. Open any project/workspace.

  3. Open the Agent panel.

  4. Ask the Agent to analyze a file (for example: “Help me optimize anhui_login.py”).

  5. The Agent stays at “Warming up…” and never returns a response.

  6. After some time, it fails with:

    • Agent Execution Timed Out
    • No first token received

  7. Open DevTools Console and observe:

    • [lansphere.cursor-retrieval] spawn
    • Unknown system error -86

  8. Running:
    /Applications/Cursor.app/Contents/Frameworks/Cursor\ Helper\ (Plugin).app/Contents/MacOS/Cursor\ Helper\ (Plugin) --version

    causes:

    • mach_vm_read invalid address (1)
    • trace trap

Operating System

MacOS

Version Information

Cursor Version:
3.7.27

OS:
macOS 27.0 Beta
Build 26A5353q

Does this stop you from using Cursor

Yes - Cursor is unusable

5

Appreciate the report! Since macOS 27 is still in beta, we can’t guarantee compatibility until the official release, but it’s on our radar.*

Would you mind sharing whether you’re running the arm64 or universal build from Cursor · Download?

And thanks for posting, this gives others a spot to flag if they’re seeing the same thing!

8

@Zhang_Hongfei is you issue resolved? I am facing exactly same issue

9

yeap, Try these steps in order:

  1. Install Rosetta 2 (most common fix): Open Terminal and run:

    softwareupdate --install-rosetta

    Then restart Cursor.

  2. Remove quarantine attributes: Fully quit Cursor and run:

    xattr -cr /Applications/Cursor.app

    Then relaunch.

  3. Disable Instant Grep indexing: Cursor Settings > Indexing & Docs > turn off “Index Repositories for Instant Grep (BETA)”, then restart Cursor. The -86 errors often originate from the retrieval extension this feature uses, which matches your console output.

  4. Try a clean profile: Run cursor --profile-temp from Terminal to rule out any configuration conflicts.

  5. Clean reinstall: If your previous reinstall didn’t involve fully deleting Cursor from Applications first, try that now and download a fresh copy from Cursor · Download.

11

Thank you. Its working now