Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

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Claude Code v2.1.248

Sandbox failure reason is withheld from untrusted output

You'll notice
Useful3 Signal2
Sandbox

Sandbox startup failure details are hidden from untrusted print-mode output.

What

In print and stream-json modes, when a sandbox is required but cannot be started, the reason is only included in the visible error for trusted invocations. Otherwise you get the bare "Sandbox required but unavailable" and the detail goes to the debug log. The full reason is still written to stderr either way.

Details
  • Trust is decided at runtime from the entrypoint and session; there is no flag to change it.
Evidence

Sandbox required but unavailable

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

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.248 →