Reading Bash-4.4 Release Available, I noticed the following sentence.
There is a new bindable variable, `colored-completion-prefix', which, if set, causes the common prefix of a set of possible completions to be displayed in color.
I tried with
export colored-completion-prefix=1 but I got an error message.
-bash: export: `colored-completion-prefix=1': not a valid identifier
set -o colored-completion-prefix 1, but I got this error message.
-bash: set: colored-completion-prefix: invalid option name
shopt -s colored-completion-prefix gave me a similar error message.
-bash: shopt: colored-completion-prefix: invalid shell option name
What does bindable variable mean, in that page? How can I set that bindable variable?
The Bash version I am running is the following one, given from CTRL + X + V in a Bash window.
GNU bash, version 4.4.12(1)-release (x86_64-pc-linux-gnu)