How to change mouse scroll speed while using libinput?

I can only find scroll methods support in libinput.

https://www.mankier.com/4/libinput http://wayland.freedesktop.org/libinput/doc/latest/group__config.html

How can I change the scroll speed of my bluetooth mouse? No relevant prop in my xinput list-props.

libinput Accel Speed (276):     0.000000
    libinput Accel Speed Default (277):     0.000000
    libinput Natural Scrolling Enabled (278):       0
    libinput Natural Scrolling Enabled Default (279):       0
    libinput Send Events Modes Available (257):     1, 0
    libinput Send Events Mode Enabled (258):        0, 0
    libinput Send Events Mode Enabled Default (259):        0, 0
    libinput Left Handed Enabled (280):     0
    libinput Left Handed Enabled Default (281):     0
    libinput Scroll Methods Available (282):        0, 0, 1
    libinput Scroll Method Enabled (283):   0, 0, 0
    libinput Scroll Method Enabled Default (284):   0, 0, 0
    libinput Button Scrolling Button (662): 2
    libinput Button Scrolling Button Default (663): 274
    libinput Middle Emulation Enabled (664):        0
    libinput Middle Emulation Enabled Default (665):        0

Solution 1:

This has been answered on Unix & Linux by meuh

In short,

there is no current api for changing the scroll speed for libinput devices

so other methods must be used to solve this issue.

Solution 2:

I am currently doing Speeding up the mouse wheel in Ubuntu 18.04 as a work around. Not particularly happy about this workaround but it does work.

Solution 3:

Implementation of this feature has been delegated to toolkits.

Here is a GNOME issue and two KDE issues tracking it:

• Ability to set scroll speed in system settings
• Libinput mouse KCM lost the scroll speed setting that was present in the evdev version and
• Libinput touchpad KCM needs a scroll speed setting