Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
0Signal: worth watching, 1 to 5
InternalsArea: what it touches
Internal ChangesKind: in v2.1.309,
Internal ChangesSection of the release
What
When Claude Code starts another program, it checks whether that program's input or output is redirected somewhere else. It used to decide this by checking whether the path began with /proc/ followed by its own process number. /proc is a special folder on Linux that describes running programs. It now compares the path with the one belonging to that input or output channel directly.
Why
This could fix passing input and output through to programs in environments where the old /proc check gave the wrong answer.
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeFixed Read reporting "File does not exist" for PDF page ranges in Linux sandboxes that share the parent's /proc
