Re: [gentoo-user] setxkbmap -option ctrl:nocaps

[Sid S]

You should be using xmodmap OR xsetkbmap OR the configuration file,
not all three (though they shouldn't interfere with each other if
configured properly - they'd just all be doing the same thing).

If you wish to set Caps_Lock to be Control_L, you need to redefine
keycode 66, not 37 (37 is Control_L by default). You may also need to
add "clear lock" or "clear Lock" before that line. Sometimes it will
or will not work if you don't do this and will toggle Caps_Lock and
press Control_L. Weird.

Alternatively, you can use xsetkbmap like you described.