bash-completion breaks with environment Variables

[Mark Jones]

Why does:

    vi $VIRTUAL_ENV/bin/postact<TAB>

become

    vi \$VIRTUAL_ENV/bin/postactactivate

on ubuntu 20.04 and

    vi $VIRTUAL_ENV/bin/postactactivate

on macOS. The Ubuntu version ruins autocomplete for this command.

macOS$ echo $BASH_VERSION
3.2.57(1)-release

ubuntu$ echo ${BASH_VERSION}
5.0.17(1)-release

Would be nice to be able to use bash-completion without is messing up so completely with reckless quoting.

Full details (including analysis of what is wrong) is here:
https://superuser.com/questions/1681581/why-does-autocomplete-vary-with-environment-variables-in-bin-bash/1681635#1681635