Last Updated: 2022-12-01
I spent hours trying to get clipboard working on a guest Ubuntu running with Virtualbox. I installed a clipboard manager, without thinking much, that supposedly supports Ubuntu.
However when I tried to copy/paste within Vim in an Ubuntu shell, it complained
$DISPLAY was none and failed. So I embarked on a long journey of trying
every possible combination of settings to get DISPLAY set, all under the
assumption that Virtualbox was suppressing it due to a config failure.
set gui=truein VIM
After a huge amount of blind trial and error, I eventually just looked up the
DISPLAY: it turns out that it's only set when there's a window
manager. Being on the command line, this of course would be unset. Nor did I want it
to be true, since I only wanted command-line access.
My error was that I had blindly chose the wrong clipboard manager, one that expected a windows-like GUI instead of just the terminal.
The lesson here is an important one, since I've fallen into such traps often:
The first port of call (e.g. here when the DISPLAY was said to be missing), should be to read the docs and thoroughly understand the behavior. Uninformed, flailing trial and error is never the solution.