You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
SandboxArea: what it touches
ImprovementsKind: in v2.1.309,
ImprovementsSection of the release
What
A sandbox is a fenced-off environment that limits what commands Claude Code runs can touch. Claude Code now has a message for when it is starting one: "Starting the sandbox… Setting file permissions can take a few minutes."
Separately, when Claude Code sorts out why access to a file path was refused, it now recognises a reason labelled name_or_place, alongside the kernel, device and credential reasons it already recognised.
Why
A slow sandbox start now comes with an explanation, so a pause at that point is less likely to look like a hang.
