Run 4 hung 10+ minutes at C4. The cause is a shell trap, not a network
one: $( ) waits for stdout to CLOSE, not for the command to exit, so a
grandchild inheriting the exec session's stdout holds the substitution
open forever — and 'timeout' does not save you, because it kills the
wrapper, not the process holding the pipe. 'claudebox exec' made it
likelier still: it becomes 'sudo -u claude -i', a login zsh with
oh-my-zsh, which is a lot of machinery to keep a fd alive.
Every in-box read now goes through in_box()/box_curl(): incus exec
directly, stdin pinned to /dev/null, output landed in a file rather than
a pipe, and 'timeout -k' to hard-kill. box_curl returns the curl exit
code as its finding — for A3 the exit code IS the answer (0 connected,
7 refused-so-it-arrived, 28 dropped). C4 also prints what it is probing
before it probes, so a stall is locatable instead of silent.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
