Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.269 ·

Eval mocks: plugins with unenumerable MCP servers now handled explicitly

Eval mocking now gives specific errors when a plugin's MCP servers can't be enumerated for mocking

TierUnder the hoodhow much it should matter to you
Useful1my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaPlugin Evalwhat it touches
KindInternal Changesin v2.1.269,
Under the hood

Eval mocking now gives specific errors when a plugin's MCP servers can't be enumerated for mocking

What

The eval mocking system can now detect and explain three specific cases where a plugin's MCP servers can't be listed for mocking:

  • the plugin is a packaged archive
  • the plugin's manifest fails to load
  • the plugin declares its servers through an MCPB bundle

Instead of failing with a generic error, record mode now tells the operator exactly what to do: extract the archive, fix the manifest, or pass --allow-real-servers.

Why

This turns a previously generic failure into an actionable message, so someone recording an eval knows exactly what's blocking it and how to resolve it.

See this entry in the whole of v2.1.269 →