Hello there.

Im using Manjaro KDE Edition (17.1.12)

CPU - Ryzen 5 1600
Mobo - Asus ROG Strix B350-F Gaming
Ram - Corsair Vengeance 3000MHz
GPU - GTX 1060 6GB (Video-Nvidia-390xx)

Blender Version 2.8
Broken: Blender 2.8 2018-09-02 Hash 41f4d210796
Worked: Blender 2.8 2018-08-24 Hash 1a7837596cb

Short description of error

Unable to composite in cycles

Exact steps for others to reproduce the error

If i start up Blender with a fresh startup file than go to the render tab and render the scene, after that i go to compositing, click on use nodes and backdrop the nodes show up as they should (still in Eevee) as soon as i switch from Eevee to Cycles something brakes as you can on my screenshot.
In Cycles the "render layer" node doesent have any outputs anymore, if i switch back to Eevee they show up again. than i can switch back to cycles and the outputs are still there, but as soon as i try to change anything the outputs are gone again.

sorry for my bad english, i hope someone understands what i am trying to say.

Sven