Documentation can't be generated on docs.rs for the wasmer-wasix crate

[Michael-F-Bryan]

Describe the bug

#3687 (in particular, 72c9d73) means the wasmer-wasix crate to no longer compile out of the box and users now are forced to set wasmer's sys or js flags explicitly.

This behaviour means the docs.rs page for wasmer-wasix v0.2.0 is broken.

Build Errors

[INFO] [stderr] error: At least the `sys` or the `js` feature must be enabled. Please, pick one.
[INFO] [stderr]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/wasmer-3.2.0-beta.2/src/lib.rs:416:1
[INFO] [stderr]     |
[INFO] [stderr] 416 | compile_error!("At least the `sys` or the `js` feature must be enabled. Please, pick one.");
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0432]: unresolved import `crate::vm::VMExternRef`
[INFO] [stderr]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/wasmer-3.2.0-beta.2/src/extern_ref.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 | use crate::vm::VMExternRef;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^ no `VMExternRef` in `vm`
[INFO] [stderr]   |
[INFO] [stderr] help: consider importing this struct instead
[INFO] [stderr]   |
[INFO] [stderr] 9 | use wasmer_vm::VMExternRef;
[INFO] [stderr]   |     ~~~~~~~~~~~~~~~~~~~~~~
[INFO] [stderr] 
[INFO] [stderr] error[E0432]: unresolved imports `crate::vm::VMExtern`, `crate::vm::VMExternFunction`, `crate::vm::VMFuncRef`, `crate::vm::VMFunctionBody`, `crate::vm::VMTrampoline`
[INFO] [stderr]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/wasmer-3.2.0-beta.2/src/externals/function.rs:8:17
[INFO] [stderr]   |
[INFO] [stderr] 8 | use crate::vm::{VMExtern, VMExternFunction, VMFuncRef, VMFunctionBody, VMTrampoline};
[INFO] [stderr]   |                 ^^^^^^^^  ^^^^^^^^^^^^^^^^  ^^^^^^^^^  ^^^^^^^^^^^^^^  ^^^^^^^^^^^^ no `VMTrampoline` in `vm`
[INFO] [stderr]   |                 |         |                 |          |
[INFO] [stderr]   |                 |         |                 |          no `VMFunctionBody` in `vm`
[INFO] [stderr]   |                 |         |                 no `VMFuncRef` in `vm`
[INFO] [stderr]   |                 |         no `VMExternFunction` in `vm`
[INFO] [stderr]   |                 no `VMExtern` in `vm`
[INFO] [stderr]   |
[INFO] [stderr]   = help: consider importing this enum instead:
[INFO] [stderr]           wasmer_vm::VMExtern
[INFO] [stderr]   = help: consider importing this struct instead:
[INFO] [stderr]           wasmer_vm::VMFuncRef
[INFO] [stderr]   = help: consider importing this struct instead:
[INFO] [stderr]           wasmer_vm::VMFunctionBody
[INFO] [stderr]   = help: consider importing this type alias instead:
[INFO] [stderr]           wasmer_vm::VMTrampoline

Solution

The docs.rs backend will check for certain metadata in your Cargo.toml to see which feature flags should be enabled while building. We should use that to tell it the wasmer/sys flag should be enabled whenever documenting the wasmer-wasix crate.

[ptitSeb]

Doc is generated now, closing.