How to reproduce:
1. Download attached project file
2. Open "scene" Scene
3. Press Play (observe the warning in the console)

Actual result: We change the render target correctly and assign a new depthtexture. However afterward we need to merge it back to the original depth texture, otherwise, the skybox will overwrite the image. However, it is impossible to find the original depth texture because it's a temporary texture. None of the Depth variants (Depth, DepthNormals, ResolvedDepth) are available. Nor is the ForwardToDepthPass exposed as a commandbufferevent.

Reproduced with: 5.6.3p2, 2017.1.1f1, 2017.2.0b10, 2017.3.0b6