Mouse bindings don't work on macOS

[nikvdp]

Hi, and thanks for this wonderful program! I've tried a lot of keymapping apps and this one is a dream come true, finally a simple and clear config language, and cross platform to boot!

I've ported my config over from the Karabiner Elements / GokuRakuJoudo and everything is working great, however for some reason on macOS mouse related bindings don't seem to have any effect.

I have the following binding in my keymapper.conf:

CapsLock{E} >> ButtonMiddle

but nothing happens when I hit CapsLock+e on mac. I'm using the same config file on a Windows machine and the binding does work as expected there, so it seems to be a mac specific issue. I've also tried WheelDown >> WheelUp as a test and that doesn't have any effect on my mac either.

In case it's helpful, I'm running keymapperd with the -v flag and I see this output at startup:

$ sudo keymapperd -v
Waiting for keymapper to connect
Resetting configuration
Active contexts received (3)
Creating virtual keyboard device 'keymapper'
Karabiner connected
Updating device list
  'keymapper' ignored (53710)
  'Razer DeathAdder Essential' grabbed (external:1:6)
  'Razer DeathAdder Essential' skipped (external:1:2)
  'Razer DeathAdder Essential' grabbed (external:1:6)
  'MD600 RGB' grabbed (external:1:6)
  'MD600 RGB' skipped (external:65280:1)
  'MD600 RGB' grabbed (external:1:128)
  'Keyboard Backlight' skipped (builtin:65280:15)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:1:2)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:65280:11)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:65280:13)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:65280:3)
  'Apple Internal Keyboard / Trackpad' grabbed (builtin:1:6)
  'BTM' skipped (external:65280:72)
  'Headset' skipped (external:12:1)
Entering update loop
Updating device list
  'keymapper' ignored (53710)
  'Razer DeathAdder Essential' already grabbed (external:1:6)
  'Razer DeathAdder Essential' skipped (external:1:2)
  'Razer DeathAdder Essential' already grabbed (external:1:6)
  'MD600 RGB' already grabbed (external:1:6)
  'MD600 RGB' skipped (external:65280:1)
  'MD600 RGB' already grabbed (external:1:128)
  'Keyboard Backlight' skipped (builtin:65280:15)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:1:2)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:65280:11)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:65280:13)
  'Apple Internal Keyboard / Trackpad' skipped (builtin:65280:3)
  'Apple Internal Keyboard / Trackpad' already grabbed (builtin:1:6)
  'BTM' skipped (external:65280:72)
  'Headset' skipped (external:12:1)

My USB mouse is the Razer DeathAdder Essential, so it seems to be getting detected. Any suggestions on how to fix it or other troubleshooting steps I could try?

Let me know if I can provide any other info or test anything to help!