Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
SessionsArea: what it touches
Internal ChangesKind: in v2.1.302,
Internal ChangesSection of the release
What
A background session is a Claude Code session that keeps running without a terminal window open in front of you. To work properly it needs a controlling terminal, which is the terminal a program belongs to and takes keyboard input and signals from. Claude Code used to find the system function that does this through a separate lookup. It now calls a function built into the runtime it ships with.
If that call cannot be made at all, Claude Code logs a message and reports the method as unavailable. If the call runs but does not succeed, it is still reported as failed.
Why
Background sessions that used to stop because the old lookup was not available may now get a terminal.
