install.sh fails on Linux: undefined unix.TIOCGETA/TIOCSETA in internal/tmux/terminal.go

[istonikula]

Summary

./install.sh fails on Linux during the "Installing cavekit command..." step because internal/tmux/terminal.go uses BSD/Darwin-only termios ioctl constants with no build tag.

Environment

• OS: Linux (amd64)
• Go: 1.26.2
• golang.org/x/sys: v0.30.0

Error

# github.com/JuliusBrussee/cavekit/internal/tmux
internal/tmux/terminal.go:11:53: undefined: unix.TIOCGETA
internal/tmux/terminal.go:27:47: undefined: unix.TIOCSETA
internal/tmux/terminal.go:37:38: undefined: unix.TIOCSETA

Root cause

unix.TIOCGETA / unix.TIOCSETA are only defined in golang.org/x/sys/unix for Darwin and the BSDs. On Linux the equivalents are unix.TCGETS / unix.TCSETS (different ioctl numbers on Linux/glibc).

internal/tmux/terminal.go has no //go:build constraint, so Go compiles it on every Unix and the build breaks on Linux. Looks like it was written/tested on macOS only.

Suggested fixes

1. Replace TIOCGETA/TIOCSETA with TCGETS/TCSETS — works on both Linux and Darwin (Darwin defines both).
2. Or split into terminal_darwin.go / terminal_linux.go with //go:build tags.
3. Simplest: use golang.org/x/term's MakeRaw / Restore, which already handles per-OS ioctl names.

Adding a Linux job to CI would catch this class of regression.