Thanks for the tmux completion post

[andresrinivasan]

I've since learned that instead of having a monolithic local bash completion file, /usr/share/bash-completion/bash_completion will look for a local directory of completions

...
__load_completion()
{
    local -a dirs=( ${BASH_COMPLETION_USER_DIR:-${XDG_DATA_HOME:-$HOME/.local/share}/b
ash-completion}/completions )
    local OIFS=$IFS IFS=: dir cmd="${1##*/}" compfile
    for dir in ${XDG_DATA_DIRS:-/usr/local/share:/usr/share}; do
        dirs+=( $dir/bash-completion/completions )
    done
    IFS=$OIFS
...