**System Information**
Operating system: Linux-5.4.0-40-generic-x86_64-with-debian-bullseye-sid 64 Bits
Graphics card: AMD Radeon RX 5700 XT (NAVI10, DRM 3.37.0, 5.4.0-40-generic, LLVM 10.0.0) X.Org 4.6 (Core Profile) Mesa 20.0.8
**Blender Version**
Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-07-19 21:23, hash: `rB78e40ad21f5b`
Tried also on 2.83.2 LTS.
**Short description of error**
Texture casts shadows where it should be transparent.
Works fine if cycles is using the CPU. The error only appears with GPU.
**Exact steps for others to reproduce the error**
# From the attached file, the error already appears as in the image. The checker texture on the left should not cast shadow where it's transparent
# if you change the particles from "hair" to "emitter", it works fine.
# move back to "hair", the error appears again
# select CPU. It works fine
# select GPU. The error appears again
{F8709097}
{F8709098}
{F8709101}
... from a later comment ...
> Trying to investigate more, I noticed that the issue is triggered when some **hair** is being rendered with GPU.
> If I do one of these, the issue doesn't appear:
> - If I exclude rendering of the hair particle system itself on the cube using the "Camera icon" toggle
> - if I entirely exclude the cube from the rendering, it works too.
> I think this is consistent with the behaviour of my first post, as switching particle type from "Hair" to "Emitter" doesn't render any hair.
>
> I add renders of this behaviour too:
> ↓ Hair particle system toggled as invisible in rendering, works, GPU
> {F8882112}
> ↓ Cube with the hair entirely excluded from rendering, works, GPU
> {F8882089}