Exclude builtins from command completion

[kaycee gb]

Hello,

For one of my projects which works with bash completion, I'm looking for a way
to exclude bash builtin commands from the completion proposals. I already had
success with exclusion of commands from PATH.

After playing with options for complete -b/-c, compgen -b/-c, these commands are
still displayed when I type first 2 letters then <TAB><TAB>

# sh<TAB><TAB>
shift shopt show

I want that it matches just the last one. 

I even tried with actions from complete enabled/disabled builtins without luck.
I'm not sure how actions work.

My bash version is 4.2.053-x86_64-2_slack14.1. 

How can I achieve what I want to do ? 

Thanks,