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Sweep 22 Oct 2026 · 21:04Z Build v2.1.309 528 read Stable v2.1.308 Latest v2.1.309 Next v2.1.309 Feeds RSS JSON llms.txt llms-full.txt Unofficial

Claude Code v2.1.251 ·

Kept eval sandboxes can be sealed after a run

Kept eval sandboxes can be sealed unreadable after a run, with ownership and path checks.

Under the hood Internal Changes
JSON All of v2.1.251
Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Plugin EvalArea: what it touches
Internal ChangesKind: in v2.1.251,
Internal ChangesSection of the release
What

The internal eval harness can now seal a sandbox directory it keeps after a run, setting it unreadable and verifying ownership, inode and that it is not the home or temp directory, with explicit failure messages on Windows and when running as root. It also indexes staging directories for stub artifacts produced during a run.

Details
  • Harness code only, not reachable from a normal session.
Evidence

eval kept-sandbox seal did not take

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.251 →

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