Auto merge of rust-lang#14444 - zapkub:runable-debug-env-is-not-passing-properly, r=Veykril

Missing runnable env on debug target

Fix bug in Rust Analyzer VSCode where runnable debugging did not pass
environment variable from configuration to child process of Cargo on binary build stage

There is a missing env passing along to `cargo` in debug target which give an in-consistent result from debug and run target

For example
```json
{
    "rust-analyzer.runnableEnv": {
        "OUT_DIR": "/test/path2"
    }
}
```

## run
![image](https://user-images.githubusercontent.com/4373581/228749503-fa55f62c-13d3-4d3c-bee6-1cfbe042bdd0.png)
## debug
compiling binary is failed. Missing env
![image](https://user-images.githubusercontent.com/4373581/228749688-3fe42efb-b5ca-41be-862d-f2d97ecab7be.png)

## debug (after fix)
![image](https://user-images.githubusercontent.com/4373581/228750057-1db60051-3465-47db-8b18-4159ec58cfdb.png)

Author: bors

editors/code/src/debug.ts

@@ -118,8 +118,8 @@ async function getDebugConfiguration(
         return path.normalize(p).replace(wsFolder, "${workspaceFolder" + workspaceQualifier + "}");
     }
 
-    const executable = await getDebugExecutable(runnable);
     const env = prepareEnv(runnable, ctx.config.runnableEnv);
+    const executable = await getDebugExecutable(runnable, env);
     let sourceFileMap = debugOptions.sourceFileMap;
     if (sourceFileMap === "auto") {
         // let's try to use the default toolchain
@@ -156,8 +156,11 @@ async function getDebugConfiguration(
     return debugConfig;
 }
 
-async function getDebugExecutable(runnable: ra.Runnable): Promise<string> {
-    const cargo = new Cargo(runnable.args.workspaceRoot || ".", debugOutput);
+async function getDebugExecutable(
+    runnable: ra.Runnable,
+    env: Record<string, string>
+): Promise<string> {
+    const cargo = new Cargo(runnable.args.workspaceRoot || ".", debugOutput, env);
     const executable = await cargo.executableFromArgs(runnable.args.cargoArgs);
 
     // if we are here, there were no compilation errors.

editors/code/src/toolchain.ts

@@ -18,7 +18,11 @@ export interface ArtifactSpec {
 }
 
 export class Cargo {
-    constructor(readonly rootFolder: string, readonly output: vscode.OutputChannel) {}
+    constructor(
+        readonly rootFolder: string,
+        readonly output: vscode.OutputChannel,
+        readonly env: Record<string, string>
+    ) {}
 
     // Made public for testing purposes
     static artifactSpec(args: readonly string[]): ArtifactSpec {
@@ -102,6 +106,7 @@ export class Cargo {
             const cargo = cp.spawn(path, cargoArgs, {
                 stdio: ["ignore", "pipe", "pipe"],
                 cwd: this.rootFolder,
+                env: this.env,
             });
 
             cargo.on("error", (err) => reject(new Error(`could not launch cargo: ${err}`)));