Swapping Ctrl, Win, and Alt in MX Linux (Xfce) – Issue with Alt Modifier

Question

I'm using MX Linux with Xfce and trying to swap three keys:

• Ctrl → Win (Super)
• Win → Alt
• Alt → Ctrl

Swapping two keys at a time works using setxkbmap, for example:

setxkbmap -option ctrl:swap_lalt_lctl

However, if I try to add a second swap, like:

setxkbmap -option ctrl:swap_lalt_lctl,altwin:swap_alt_win

I end up with a repetition of the same key instead of a clean three-way swap.

Attempted Solution

I created a custom XKB symbols file:

xkb_symbols "ctrl_win_alt_swap" {
    include "us"  // Keep the default US layout
    key <LCTL> { [ Super_L ] };  // Left Ctrl → Left Win
    key <LWIN> { [ Alt_L ] };    // Left Win → Left Alt
    key <LALT> { [ Control_L ] }; // Left Alt → Left Ctrl
};

I apply this with:

setxkbmap -layout custom -variant ctrl_win_alt_swap

The remapping works, except for one issue:

• Pressing Alt alone produces Ctrl, which is expected.
• Pressing Alt in combination with another key results in Ctrl+Alt, instead of just Ctrl.

Why does this happen, and how can I properly swap Ctrl, Win, and Alt without modifier conflicts?

Answer 1

After reading more carefully the instructions of setxkbmap I found there is a specially defined option to swap all the three keys:

$ setxkbmap -option ctrl:swap_lalt_lctl_lwin