substrate/utils: enable wasm builder diagnostics propagation (#5838)
# Description `substrate-wasm-builder` can be a build dependency for crates which develop FRAME runtimes. I had a tough time seeing errors happening in such crates (e.g. runtimes from the `templates` directory) in my IDE. I use a combination of rust-analyzer + nvim-lsp + nvim-lspconfig + rustacean.vim and all of this stack is not able to correctly parse errors emitted during the `build` phase. As a matter of fact there is also a cargo issue tracking specifically this issue where cargo doesn't propagate the `--message-format` type to the build phase: [here](https://github.com/rust-lang/cargo/issues/14246) initially and then [here](https://github.com/rust-lang/cargo/issues/8283). It feels like a solution for this use case isn't very close, so if it comes to runtimes development (both as an SDK user and developer), enabling wasm builder to emit diagnostics messages friendly to IDEs would be useful for regular workflows where IDEs are used for finding errors instead of manually running `cargo` commands. ## Integration It can be an issue if Substrate/FRAME SDKs users and developers rely on the runtimes' crates build phase output in certain ways. Emitting compilation messages as json will pollute the regular compilation output so people that would manually run `cargo build` or `cargo check` on their crates will have a tougher time extracting the non JSON output. ## Review Notes Rust IDEs based on rust-analyzer rely on cargo check/clippy to extract diagnostic information. The information is generated by passing flags like `--messages-format=json` to the `cargo` commands. The messages are extracted by rust-analyzer and published to LSP clients that will populate UIs accordingly. We need to build against the wasm target by using `message-format=json` too so that IDEs can show the errors for crates that have a build dependency on `substrate-wasm-builder`. --------- Signed-off-by:Iulian Barbu <[email protected]> Co-authored-by:
Bastian Köcher <[email protected]>