`impl_runtime_apis` does not work if `sp-api` is not in scope

[kianenigma]

Somewhat similar to paritytech/polkadot-sdk#173, it seems like this macro also does not work if sp-api is not directly in scope as a dependency. The error message is very cryptic:

error: proc macro panicked
   --> staging-runtime/src/lib.rs:114:1
    |
114 | / impl_runtime_apis! {
115 | |     impl frame_runtime::runtime_apis::Core<Block> for Runtime {
116 | |         fn version() -> RuntimeVersion {
117 | |             VERSION
...   |
177 | |     }
178 | | }
    | |_^
    |
    = help: message: unexpected token

This prevents eg. #14137 to re-export sp_api::Core and impl_runtime_apis in a way that is meaningfully usable.

Note that for rest of the APIs, like sp_block_builder you can import it from a 3rd party re-export them from somewhere else and it works. Although, you need make sure to re-export them like pub use sp_block_builder::* to re-export some magic generated by decl_runtime_apis! as well.

[bkchr]

It should for sure not panic, but otherwise it uses the same logic as in FRAME.

[kianenigma]

Moreover, if sp-api is imported without any notion of disabling default features, like:

sp-api = { git = "https://github.com/paritytech/substrate.git", branch = "kiz-frame-api" }

we get the following error:

error[E0425]: cannot find function `to_substrate_wasm_fn_return_value` in crate `sp_api`
   --> staging-runtime-native/src/lib.rs:114:1
    |
114 | / impl_runtime_apis! {
115 | |     impl frame_runtime::runtime_apis::Core<Block> for Runtime {
116 | |         fn version() -> RuntimeVersion {
117 | |             VERSION
...   |
177 | |     }
178 | | }
    | |_^ not found in `sp_api`
    |
    = note: this error originates in the macro `impl_runtime_apis` (in Nightly builds, run with -Z macro-backtrace for more info)

[kianenigma]

Can this be fixed in a timely fashion? if we can fix it sooner, I won't need to go and refactor infinite number of branches in the tutorial late 🙈

[bkchr]

we get the following error:

Did you read what I have written in element? The same applies for all FRAME macros as well...

[kianenigma]

@bkchr do you have any plans to address this? I initially thought the #14267 is going to fix this, but I was wrong.

Saw your comment here #14267 (comment).

[kianenigma]

closed in 7d912d0