Error if using `..` at the root of the virtual directory hierarchy.

[chriseth]

I guess this could help many people solving their import problems and would also prevent mistakes.

[github-actions]

Hi everyone! This issue has been closed due to inactivity.
If you think this issue is still relevant in the latest Solidity version and you have something to contribute, feel free to reopen.
However, unless the issue is a concrete proposal that can be implemented, we recommend starting a language discussion on the forum instead.

[cameel]

I think this is still relevant. When it happens, behavior of the compiler is quite unintuitive to users, though they probably do not even realize what is the source of the problem.