There is a new pull request by st3r4g against master on the void-packages repository

https://github.com/st3r4g/void-packages nvidia390-fix-libGL-conflict
https://github.com/void-linux/void-packages/pull/15337

nvidia390: fix libGL dependency conflict
Trying to include the package `nvidia390` in a live image:
`sudo ./mklive.sh -a x86_64 -r https://alpha.de.repo.voidlinux.org/current/nonfree -p nvidia390`

Failed with:

> nvidia390-libs-390.129_1: collecting files...
ERROR: nvidia390-libs-390.129_1: file `/usr/lib/libEGL.so.1' already installed by package libEGL-19.1.7_3.
ERROR: nvidia390-libs-390.129_1: file `/usr/lib/libGL.so.1' already installed by package libGL-19.1.7_3.
ERROR: nvidia390-libs-390.129_1: file `/usr/lib/xorg/modules/extensions/libglx.so' already installed by package libGL-19.1.7_3.
Transaction failed! see above for errors.
ERROR: Failed to install base-system nvidia390

The reason is that `nvidia390-gtklibs` pulls in `cairo` which in turn installs the Mesa implementation of `libGL` (ignoring the `libGL` provided by Nvidia). I fixed this looking at how the `nvidia` template deals with it, I don't know if it's the optimal solution.

A patch file from https://github.com/void-linux/void-packages/pull/15337.patch is attached