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.

All of v2.1.247 Home All releases olderv2.1.246 v2.1.248newer
Claude Code v2.1.247

claude attach tells you whether the terminal host died or just never answered

Use it now
Useful4 Signal3
Sessions

Attach failures now distinguish a dead terminal host from a silent session, and offer the right recovery.

claude attach
What

Attach failures used to collapse into a generic "couldn't attach". Two causes are now separated. A session whose terminal host died is restarted on a fresh host, automatically on the command line and on the next Enter in the picker. A session that simply did not answer is offered a stop-and-attach cycle, with a note that the conversation is saved. Sessions you adopted from a shell command get different wording, because their command is not re-run for you.

Details
  • The two cases are recognised from the prefix on the error the background daemon returns, and are reported separately in telemetry.
  • The daemon's liveness check now also spots a worker that has become a zombie and SIGKILLs its whole process group before declaring the session gone.
  • Unconditional; no flag involved.
Evidence

job_attach_host_dead

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 v2.1.247 →