libinput error: libinput bug: Device 'Wacom BambooPT 2FG Small Pad'
does not meet tablet criteria. Ignoring this device. Device:
Power Button Kernel:           /dev/input/event1
Group:            1
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           Power Button
Kernel:           /dev/input/event0
Group:            2
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           DELL Dell USB Entry Keyboard
Kernel:           /dev/input/event2
Group:            3
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           Wacom BambooPT 2FG Small Pen
Kernel:           /dev/input/event3
Group:            4
Seat:             seat0, default
Size:             147.20x92.00mm
Capabilities:     tablet 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   none
Rotation:         n/a

Device:           Wacom BambooPT 2FG Small Finger
Kernel:           /dev/input/event4
Group:            4
Seat:             seat0, default
Size:             120.00x80.00mm
Capabilities:     pointer 
Tap-to-click:     enabled
Tap-and-drag:     enabled
Tap drag lock:    disabled
Left-handed:      disabled
Nat.scrolling:    disabled
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   *two-finger edge 
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   none
Rotation:         n/a

How do you debug this?

Not that I care that much, anyway. I was debugging other problem when seeing
this error.