Custom Depth Buffer not working in latest engine 1.x (1.77.0)

[aidinabedi]

I've created the following test project which reproduces the issue: https://playcanvas.com/project/1418452/overview/depth-buffer-test

Steps to reproduce the issue

1. Launch project in latest engine 1.x (1.77.0.)
2. Observe results:

Expected results

Launched in latest engine 2.x (2.13.4) to see expected results:

[mvaligursky]

Can you please explain what the example does. What does the custom depth buffer means?
And what does not work specifically as far as you can tell.

[aidinabedi]

By custom depth buffer, I mean using a depth texture like so:

    this.depthBuffer = new pc.Texture(device, {
        width: device.width,
        height: device.height,
        format: pc.PIXELFORMAT_DEPTH,
        mipmaps: false,
        minFilter: pc.FILTER_NEAREST,
        magFilter: pc.FILTER_NEAREST,
        addressU: pc.ADDRESS_CLAMP_TO_EDGE,
        addressV: pc.ADDRESS_CLAMP_TO_EDGE
    });

    this.renderTarget = new pc.RenderTarget({
        colorBuffer: this.colorBuffer,
        depthBuffer: this.depthBuffer
    });

Rather than just using the built-in depth buffer:

    this.renderTarget = new pc.RenderTarget({
        colorBuffer: this.colorBuffer,
        depth: true
    });

If you compare the resulting depth texture between engine 1.77.0 and 2.13.4, you see that the former produces a texture that's unusable:

The whole point of using a depth texture is to avoid having to redraw the entire scene in a special rendering pass, which is what the engine does when using depth grabpass (which is costly).

[mvaligursky]

from the screenshots it seems that the depth buffer on left is not cleared each frame