logname(1) returns root on macOS, instead of current user

[dennisse]

What Operating System(s) are you seeing this problem on?

macOS 15.0 Sequoia

Which Wayland compositor or X11 Window manager(s) are you using?

N/A

WezTerm version

20240922-151228-2b76c63b

Did you try the latest nightly build to see if the issue is better (or worse!) than your current version?

Yes, and I updated the version box above to show the version of the nightly that I tried

Describe the bug

When running logname(1) on macOS, it returns root, not the name of the current user.

In Terminal.app and Kitty, the command returns the current user.

To Reproduce

Just run logname(1)

(zsh) % logname
root

(bash) $ logname
root

Configuration

None

Expected Behavior

logname(1) should return the username of the current user.

Logs

N/A

Anything else?

The discussion at kovidgoyal/kitty#6511 seems be related. This is the solution they landed on.

logname(1) calls getlogin(2), and getlogin(2) should return the correct username under a login-shell, but it doesn't.

Launching the shell with login(1) make logname(1) behave as expected, so here is my workaround:

if wezterm.target_triple:find("darwin") ~= nil then
  local USER = os.getenv("USER")
  local SHELL = os.getenv("SHELL")
  config.default_prog = { '/usr/bin/login', '-fpq', USER, SHELL, '-li' }
end