Terminal width probe fails under Claude Code ≥ 2.1.139 (no controlling TTY for spawned statusline) #376

Summary

On Linux under Claude Code ≥ 2.1.139, ccstatusline's TTY-width probe fails entirely and falls back to tput cols → 80. With the default flexMode: "full-minus-40", the statusline truncates at 40 columns regardless of actual terminal width.

Root cause

Claude Code 2.1.139 changelog:

Fixed a bug where a hook writing to the terminal could corrupt an on-screen interactive prompt; hooks now run without terminal access.

The statusLine spawn is hardened the same way. The ancestor walk in probeTerminalWidth correctly finds the controlling PTY, but getWidthForTTY's stty size < /dev/${tty} form fails with ENOTTY when the calling process has no controlling terminal.

Reproduction

$ stty size < /dev/pts/0
stty: Inappropriate ioctl for device
$ stty -F /dev/pts/0 size
36 159

Reproducible without ccstatusline via setsid -w bash -c 'stty size < /dev/pts/0' — confirms it's generic, not terminal-emulator-specific.

Fix

Use stty -F <path> size (GNU coreutils) or stty -f <path> size (BSD); they open the device internally and succeed regardless of controlling-tty status. PR coming.

Related

Open requests to expose terminal.width in the statusLine JSON, which would future-proof this independently:

• request: Pass available width(s) to statusLine command hook anthropics/claude-code#5430
• statusLine: pass terminal columns to command via stdin or env, and account for visual line wrapping anthropics/claude-code#22115