Comment 0 for bug 1769857

OS: Ubuntu 18.04 bionic
Kernel: x86_64 Linux 4.15.0-20-generic
CPU: Intel Core i5-7200U @ 4x 3.1GHz
GPU: Intel HD 620 + NVIDIA GeForce 940MX (Optimus)
UEFI boot, Secure Boot disabled.

I installed the proprietary graphics driver with Software Properties and Vulkan applications (e.g. vulkan-smoketest, Unreal Editor, SDK examples, Dolphin) were working fine.
To get rid of tearing I added nvidia-drm.modeset=1 to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub, then ran update-grub && update-initramfs -u and rebooted.
After doing that, Vulkan applications stopped working because they couldn't initialize the Vulkan swap chain until I reverted the changes to GRUB.

Other GNU/Linux distributions such as Manjaro don't seem to be affected which is why I'm reporting this here.