COMP_LINE not set despite bash completion being installed

Question

I'm using homebrew's bash completion package on OSX, which is installed in /usr/local/etc/bash_completion. It's working fine, but there are many extensions for it which rely on various environment variables beginning with COMP_, such as COMP_LINE. These environment variables unfortunately aren't being exported into my bash environment, despite the fact that the proper files are being sourced. Here is the applicable area in my .bash_profile:

# bash completion
if [ -f `brew --prefix`/etc/bash_completion ]; then
  . `brew --prefix`/etc/bash_completion
  . /usr/local/etc/bash_completion.d/git-completion.bash
fi

Yet COMP_LINE isn't set, which is preventing other completion addons from working:

> env | grep COMP_LINE
>

Any ideas why the environment variables aren't set? Thanks in advance for your time.

Answer 1

$COMP_LINE is not an environment variable. It is an internal variable, and it's only visible to the completion functions, not to other shell usage. (Most other internal variables are visible in declare.)