forkpty failures throw PtyException with the captured errno
(previously a generic StateError). The spawned child's chdir/execve
failures write a diagnostic line to its slave PTY before _exit, so
the parent's reader sees "exec failed: <path>" instead of an
indistinguishable EOF.
NativePty.write and PtySession.write loop on short writes and throw
PtyException on hard errors (with errno). NativePty.resize sets
_dead on EBADF so subsequent calls short-circuit cleanly.
Co-Authored-By: Claude <noreply@anthropic.com>
jpmschweitzerandClaude
0d333e8470