There is an updated pull request by CameronNemo against master on the void-packages repository

https://github.com/CameronNemo/void-packages lxc-4.0.0
https://github.com/void-linux/void-packages/pull/20500

[DONOTMERGE] lxc: update to 4.0.0.
4.0.1 should be released soon, then this PR will be updated.

A patch file from https://github.com/void-linux/void-packages/pull/20500.patch is attached