GitHub Copilot CLI error
Copilot CLI: posix_spawnp failure
posix_spawnp failureStatus: Fixed in releaseLast verified 2 documented fixes2 sources
What it means
After long use, the bash tool can no longer start a new shell (pseudo-terminal), so every shell command fails.
Causes
- A pseudo-terminal file-descriptor leak. Maintainer djdefi (MEMBER): "Each
bashtool call allocates a PTY that isn't properly released" and "Eventuallyposix_spawnfails with ENOENT when trying to allocate a new PTY". The leak was traced to the bundled node-pty and to the CLI's shell session handling.
How to fix it
- Fix 1.
Upgrade to 0.0.407 or later: "Updated node-pty to fix file descriptor leaks". Maintainer MRayermannMSFT: "Just merged the
node-ptyupdate. Will go out in next release." - Fix 2.
Workaround on older versions from djdefi: "Restart copilot CLI sessions periodically (we restart daily)."
More Copilot CLI errors
All 12 Copilot CLI errors✗ No model available. Check policy enablement under GitHub Settings > CopilotStatus: Fixed in releaseYou are not authorized to use this Copilot feature, it requires an enterprise or organization policy to be enabled.Status: By designRequest failed due to a transient API error. Retrying...Status: Open✗ Execution failed: Error: Failed to get response from the AI model; retried 5 times (total retry wait time: 5.927545045390875 seconds) Last error: Unknown errorStatus: Fixed in releaseCAPIError: 400 {"message":"","code":"invalid_request_body"}Status: OpenExecution failed: CAPIError: 400 {"error":{"code":"bad_request","type":"websocket_error","message":"Duplicate item found with id fc_call_ikBrgmi06fcJeO6uIpJJEQbJ. Remove duplicate items from your input and try again."}}Status: Open✗ Model call failed: "Connection error." ✗ Execution failed: CAPIError: Connection error.Status: Fixed in releaseServer failed to connectStatus: Fixed in release
Related reading
- How to Measure AI Coding Tool ROI in 2026How to measure AI coding tool ROI for Claude Code, Cursor and Copilot: a framework with benchmarks, cost models and metrics that hold up past vendor 10x claims.
- Claude Code vs Codex vs Copilot CLI: Local Sandboxes ComparedCopilot CLI local sandboxing is GA. How it compares with Claude Code and Codex on defaults, network, credentials, Windows, and what still runs outside.
- GitHub Copilot CLI With Ollama: Local Models and the New SandboxCopilot CLI 1.0.94 finds local Ollama models from /model and ships an OS-level sandbox. Setup, the 4k context trap, and why local is not offline.
- Claude Sonnet 5.5 Developer Guide: Pricing and API ChangesClaude Sonnet 5.5 costs $2/$10 per million tokens, and cache reads fell to $0.10 on October 7 - half of Opus 5.5 on every line. Pricing math and API changes.
- GitHub Copilot's September Reset: Prepaid Seats, One Unified Agent Experience, Balanced Reviews by DefaultGitHub Copilot September changes: prepaid Business and Enterprise seats, one unified agent experience and Balanced reviews by default. What it means for teams.
- GitHub's August 17 Outage: Agent Fleets Need a 4-Hour Local FallbackGitHub's August 17 outage ran 7 hours 47 minutes across PRs, Actions, APIs and Copilot. Why coding agent fleets need a four-hour local fallback.
FAQ
What does "posix_spawnp failure" mean in Copilot CLI?
After long use, the bash tool can no longer start a new shell (pseudo-terminal), so every shell command fails.
How do I fix "posix_spawnp failure"?
There are 2 documented fixes. Start with the first: Upgrade to 0.0.407 or later: "Updated node-pty to fix file descriptor leaks". Maintainer MRayermannMSFT: "Just merged the node-pty update. Will go out in next release."
Is this Copilot CLI error fixed?
Status: Fixed in release. A release fixed this. The affected versions note says where the fix landed. Affected versions: 0.0.358 to 0.0.406. Fixed in 0.0.407 (2026-02-11).
Sources
Last verified against 2 sources: official docs, maintainer replies and release notes.
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