Thanks for investigating!
First success:
using GLFW
present = GLFW.JoystickPresent(GLFW.JOYSTICK_1)
returns true
And this also works:
while true
axis = GLFW.GetJoystickAxes(GLFW.JOYSTICK_1)
buttons = GLFW.GetJoystickButtons(GLFW.JOYSTICK_1)
println(axis, " ", buttons)
sleep(0.1)
end