Naga fails to build: "unresolved import back::continue_forward"

[jimblandy]

Naga fails to build as follows (which happens to be the way Firefox uses it):

$ cargo build --target=x86_64-pc-windows-msvc --features="dx12 vulkan"
   Compiling naga v22.0.0 (/home/jimb/rust/wgpu/naga)
   Compiling wgpu-core v22.0.0 (/home/jimb/rust/wgpu/wgpu-core)
   Compiling d3d12 v22.0.0 (/home/jimb/rust/wgpu/d3d12)
error[E0432]: unresolved import `back::continue_forward`
    --> naga/src/back/hlsl/writer.rs:1574:19
     |
1574 |         use back::continue_forward::ExitControlFlow;
     |                   ^^^^^^^^^^^^^^^^ could not find `continue_forward` in `back`

error[E0433]: failed to resolve: could not find `continue_forward` in `back`
   --> naga/src/back/hlsl/writer.rs:107:33
    |
107 |             continue_ctx: back::continue_forward::ContinueCtx::default(),
    |                                 ^^^^^^^^^^^^^^^^ could not find `continue_forward` in `back`

error[E0433]: failed to resolve: could not find `continue_forward` in `back`
   --> naga/src/back/hlsl/mod.rs:330:25
    |
330 |     continue_ctx: back::continue_forward::ContinueCtx,
    |                         ^^^^^^^^^^^^^^^^ could not find `continue_forward` in `back`

Some errors have detailed explanations: E0432, E0433.
For more information about an error, try `rustc --explain E0432`.
error: could not compile `naga` (lib) due to 3 previous errors
$ 

[jimblandy]

The problem seems to be that, in naga/src/back/mod.rs, we have:

#[cfg(hlsl_out)]
pub mod hlsl;
...
#[cfg(any(feature = "hlsl-out", feature = "glsl-out"))]
mod continue_forward;

So the naga::back::hlsl is using the cfg_aliases aliases, but naga::back::continue_forward is using the old features.