= version requirements are fragile. This will irreparably break builds for any dependent who has another dependency requiring a newer version of web_sys, and isn't even using the unstable apis part of wgpu (which could be webgl backend only, or even a non-web build that happens to also have an unused web_sys dep somewhere else).

This would be worthwhile if wgpu always used web_sys_unstable_apis, but it doesn't.

It certainly will break builds for some users, but they will break upfront.

The current approach allows for Wasm builds to break after the fact, in code that has already been released.

In fact, 0.19 is actually broken right now.

This imposes a very large cost on all users of only stable features ("don't upgrade your other dependencies") in order to benefit users of unstable features.

Hmm, would it be possible to have two web-sys dependencies declared, one pinned and one not, and the pinned one only enabled when webgpu is enabled? If Cargo accepts that, it would handle both cases well.

This doesn't solve the immediate problem, but: We currently plan on upgrading web-sys to address (see #5148, #5188). Notice that I was the one who filed wasm-bindgen/wasm-bindgen#3816.

Hmm, would it be possible to have two web-sys dependencies declared, one pinned and one not, and the pinned one only enabled when webgpu is enabled? If Cargo accepts that, it would handle both cases well.

It may be possible with a bit of conditional compilation. I'll look into it.