Merge #4329

4329: Look for `cargo`, `rustc`, and `rustup` in standard installation path r=matklad a=cdisselkoen

Discussed in #3118.  This is approximately a 90% fix for the issue described there.

This PR creates a new crate `ra_env` with a function `get_path_for_executable()`; see docs there.  `get_path_for_executable()` improves and generalizes the function `cargo_binary()` which was previously duplicated in the `ra_project_model` and `ra_flycheck` crates.  (Both of those crates now depend on the new `ra_env` crate.)  The new function checks (e.g.) `$CARGO` and `$PATH`, but also falls back on `~/.cargo/bin` manually before erroring out.  This should allow most users to not have to worry about setting the `$CARGO` or `$PATH` variables for VSCode, which can be difficult e.g. on macOS as discussed in #3118.

I've attempted to replace all calls to `cargo`, `rustc`, and `rustup` in rust-analyzer with appropriate invocations of `get_path_for_executable()`; I don't think I've missed any in Rust code, but there is at least one invocation in TypeScript code which I haven't fixed.  (I'm not sure whether it's affected by the same problem or not.) https://github.com/rust-analyzer/rust-analyzer/blob/a4778ddb7a00f552a8e653bbf56ae9fd69cfe1d3/editors/code/src/cargo.ts#L79

I'm sure this PR could be improved a bunch, so I'm happy to take feedback/suggestions on how to solve this problem better, or just bikeshedding variable/function/crate names etc.

cc @Veetaha 

Fixes #3118.

Co-authored-by: Craig Disselkoen <[email protected]>
Co-authored-by: veetaha <[email protected]>

1 files changed, 5 insertions, 2 deletions

diff --git a/editors/code/src/commands/runnables.ts b/editors/code/src/commands/runnables.ts
index d77e8188c..2ed150e25 100644
--- a/editors/code/src/commands/runnables.ts
+++ b/editors/code/src/commands/runnables.ts
@@ -119,8 +119,11 @@ export function debugSingle(ctx: Ctx): Cmd {
         }
 
         if (!debugEngine) {
-            vscode.window.showErrorMessage(`Install [CodeLLDB](https://marketplace.visualstudio.com/items?itemName=${lldbId})`
-                + ` or [MS C++ tools](https://marketplace.visualstudio.com/items?itemName=${cpptoolsId}) extension for debugging.`);
+            vscode.window.showErrorMessage(
+                `Install [CodeLLDB](https://marketplace.visualstudio.com/items?itemName=${lldbId}) ` +
+                `or [MS C++ tools](https://marketplace.visualstudio.com/items?itemName=${cpptoolsId}) ` +
+                `extension for debugging.`
+            );
             return;
         }