refactor!: rename project to bot-bottle

Assisted-by: Codex

bot_bottle/backend/smolmachines/pty_resize.py

@@ -0,0 +1,149 @@
+"""Host-side SIGWINCH → in-VM PTY resize bridge (issue #82).
+
+smolvm 0.8.0 `machine exec -t` allocates an in-VM PTY but never
+forwards the host terminal's window size (TIOCSWINSZ) to it. The
+PTY's initial size is `0 0`, and any host-side resize during the
+session goes unnoticed — the in-VM claude TUI keeps rendering for
+whatever (typically tiny) box it last saw, ignoring the operator's
+tmux pane resize. `docker exec -it` does this forwarding
+automatically; smolvm doesn't.
+
+This module wraps `smolvm machine exec` with a thin parent
+process that:
+
+  1. Spawns the original argv as a child (it gets the inherited
+     TTY, so claude's stdin/stdout/stderr work unchanged).
+  2. On startup + every host SIGWINCH, reads the host terminal
+     size via TIOCGWINSZ on stdin (or stderr if stdin isn't a
+     TTY — tmux respawn-pane gives us a TTY on stdout/stderr)
+     and pushes it into the VM with a side-channel
+     `smolvm machine exec -- sh -c 'for f in /dev/pts/*; do
+     stty -F $f cols X rows Y; done'`. The kernel delivers
+     SIGWINCH to the foreground process group on the slave end
+     automatically, so claude picks up the new size without
+     extra signalling.
+  3. Waits on the child and exits with its returncode.
+
+The dashboard's tmux pane respawn calls `bottle.claude_argv`
+which now prepends `[sys.executable, -m, ..., <machine>, --, ...]`
+to the smolvm argv. Foreground handoff (curses endwin →
+subprocess.run) goes through the same path so behavior is
+identical.
+
+Removable once smolvm grows native SIGWINCH forwarding (upstream
+follow-up tracked separately)."""
+
+from __future__ import annotations
+
+import fcntl
+import signal
+import struct
+import subprocess
+import sys
+import termios
+import threading
+
+
+# How long to wait after the main exec starts before pushing the
+# initial size. Concurrent `smolvm machine exec` invocations race
+# libkrun's per-exec OCI config write during the main exec's
+# bringup window; the side-channel firing immediately corrupts
+# `config.json` and the main exec dies with SIGKILL (rc=137) or
+# libkrun's "parse error: trailing garbage" depending on
+# scheduling. Two seconds is well past the bringup window on a
+# warm VM, well under the operator's "this is unresponsive"
+# threshold, and short enough that claude's initial render
+# almost always fires after the size has been set.
+_STARTUP_SYNC_DELAY_SEC = 2.0
+
+
+def _read_winsize() -> tuple[int, int] | None:
+    """Return `(rows, cols)` from whichever of stdin / stdout /
+    stderr is a TTY, or None if none are. Different invocation
+    surfaces give us different TTYs:
+
+      - foreground handoff (curses endwin → subprocess.run): all
+        three are the operator's terminal.
+      - tmux respawn-pane: tmux sets all three to the pane's PTY.
+      - non-TTY (someone piped stdin in tests): none are; the
+        sync just no-ops, which is the right behavior."""
+    for fd in (sys.stdin.fileno(), sys.stdout.fileno(), sys.stderr.fileno()):
+        try:
+            data = fcntl.ioctl(fd, termios.TIOCGWINSZ, b"\x00" * 8)
+        except OSError:
+            continue
+        rows, cols, _, _ = struct.unpack("hhhh", data)
+        if rows > 0 and cols > 0:
+            return rows, cols
+    return None
+
+
+def _push_size(machine: str, rows: int, cols: int) -> None:
+    """Side-channel `smolvm machine exec` that sets the size of
+    every PTY in the VM. The shell `for` loop covers the case of
+    multiple concurrent interactive sessions (rare but cheap to
+    handle); `stty -F` returns silently on PTYs that don't apply.
+
+    Best-effort: swallow failures. A failed resize doesn't break
+    the session — it just leaves the in-VM PTY at its old size.
+
+    `stdin=DEVNULL` is load-bearing: under tmux, inheriting the
+    pane PTY here means two concurrent smolvm processes (this one
+    and the agent session the wrapper is shepherding) share the
+    PTY's foreground-process-group / input plumbing, and smolvm
+    bails with an internal config-parse error or SIGKILL within
+    ~100ms of the side-channel firing. Outside tmux the same
+    pattern survived, presumably because iTerm's PTY plumbing is
+    more forgiving than tmux's, but the DEVNULL is the right
+    default either way — the side-channel never needs stdin."""
+    subprocess.run(
+        ["smolvm", "machine", "exec", "--name", machine, "--",
+         "sh", "-c",
+         f"for f in /dev/pts/*; do "
+         f"stty -F \"$f\" cols {cols} rows {rows} 2>/dev/null; "
+         f"done"],
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+        check=False,
+    )
+
+
+def main(argv: list[str]) -> int:
+    """Entry point. `argv` shape: `<machine> -- <smolvm-argv...>`.
+
+    We don't use argparse — the `--` separator is the contract and
+    everything past it is forwarded verbatim. Keeps the wrapper
+    transparent for callers building argv programmatically."""
+    if len(argv) < 3 or argv[1] != "--":
+        sys.stderr.write(
+            "usage: python -m bot_bottle.backend.smolmachines.pty_resize "
+            "<machine> -- <smolvm-argv...>\n"
+        )
+        return 2
+    machine = argv[0]
+    inner = argv[2:]
+
+    def sync(*_args) -> None:
+        size = _read_winsize()
+        if size is None:
+            return
+        _push_size(machine, *size)
+
+    signal.signal(signal.SIGWINCH, sync)
+
+    proc = subprocess.Popen(inner)
+    # Initial sync is deferred — see _STARTUP_SYNC_DELAY_SEC.
+    # daemon=True so the timer doesn't block exit when the child
+    # finishes before the delay elapses.
+    timer = threading.Timer(_STARTUP_SYNC_DELAY_SEC, sync)
+    timer.daemon = True
+    timer.start()
+    while True:
+        try:
+            return proc.wait()
+        except KeyboardInterrupt:
+            proc.send_signal(signal.SIGINT)
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))