... it from either /etc/bashrc or ~/.bashrc (or any other file sourcing those). If you don't have the package readily available for your distribution, or you simply don't want to use one, you can install bash-completion using the standard commands for GNU Autotools packages. If you find that a given function is producing errors or does not work as it should under certain circumstances when you attempt completion, try running set -x or set -v prior to attempting the completion again.