Suggestion: Emit clear warning or error if resolver = "2" is missing in multi-package workspaces

[n4t4l]

After moving a compute shader study project to a multi-package workspace and setting up a shared asset folder, I encountered an unreachable code panic deep in Naga during shader pipeline compilation. At first, I thought it was caused by the shared folder or a bug in my shaders.

However, I later discovered that the error occurred in any multi-package Bevy project that had both asset creation and a camera — regardless of the actual shaders used. I spent hours trying to identify the issue: clearing caches, resetting my Rust environment, updating/downgrading graphics drivers, etc.

Eventually, I found that the root cause was simply that my workspace's Cargo.toml was missing:

[workspace]
resolver = "2"

Once I added that, the problem disappeared immediately.

After the fact I've realized this is mentioned in the quick-start guide, but by the time this kind of failure happens — possibly days or weeks into a project — most users won’t think to find solutions there. And the error message points to naga::back::glsl or naga_oil, so it’s easy to get misled into debugging shaders or asset loading code instead.

Would it be possible to:

• Emit a warning or error at runtime or build time if resolver = "2" is not set in a workspace?
• Or, at the very least, add a diagnostic pointing to this from the panic?

Thanks for the amazing work on Bevy!