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Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.308 Feeds RSS JSON llms.txt llms-full.txt Unofficial
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Claude Code v2.1.304 ·

Sandbox reports unavailable at once in some sessions

In some sessions the sandbox check now fails straight away with "The sandbox is unavailable in this session"

You'll notice Improvements
JSON All of v2.1.304
You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
SandboxArea: what it touches
ImprovementsKind: in v2.1.304,
ImprovementsSection of the release

Unclear Which sessions are affected, and so who cannot use the sandbox, is not known.

What

The sandbox is a closed-off area that limits what commands Claude runs can do. Before using it, Claude Code checks that the programs it needs are installed. In some sessions it now skips that check and reports "The sandbox is unavailable in this session" straight away. Before, it always ran the check.

Why

In those sessions the sandbox is reported as unavailable rather than tried.

How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtWhich sessions are affected, and so who cannot use the sandbox, is not known.

See this entry in the whole of v2.1.304 →

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