Remove the RUST_SRC_PATH environment variable

If the RUST_SRC env var was already set, we should keep that value and not change it.
If it was not set, rust-analyzer is very well capable of finding that path on its own.

Fixes #184

Author: msrd0

lib/index.js

@@ -142,26 +142,6 @@ function shouldIgnoreProjectPath(projectPath) {
     .some(path => path === projectPath.trim().replace(/[/\\]*$/, ''))
 }
 
-/**
- * @param {string} [toolchain]
- * @param {string} [cwd]
- * @return {Promise<string>} `rustc --print sysroot` stdout
- */
-async function rustcSysroot(toolchain, cwd) {
-  try {
-    let { stdout } = await rustupRun(toolchain, "rustc --print sysroot", { cwd })
-    return stdout.trim()
-  } catch (e) {
-    // make an attempt to use system rustc
-    try {
-      let { stdout } = await exec(`rustc --print sysroot`, { cwd })
-      return stdout.trim()
-    } catch (sys_e) {
-      throw e
-    }
-  }
-}
-
 /** @return {string} environment variable path */
 let envPath = () => {
   // Make sure the cargo directory is in PATH
@@ -176,7 +156,7 @@ let envPath = () => {
  * @param {string} [cwd]
  * @return {Promise<object>} environment vars
  */
-async function serverEnv(toolchain, cwd) {
+function serverEnv() {
   const env = process.env
   env.PATH = envPath()
   env.RUST_BACKTRACE = env.RUST_BACKTRACE || "1"
@@ -185,12 +165,6 @@ async function serverEnv(toolchain, cwd) {
   //   env.RUST_LOG = 'info'
   // }
 
-  try {
-    let sysroot = await rustcSysroot(toolchain, cwd)
-    env.RUST_SRC_PATH = path.join(sysroot, "/lib/rustlib/src/rust/src/")
-  } catch (e) {
-    console.warn("Failed to find sysroot: " + e)
-  }
   return env
 }
 
@@ -553,7 +527,7 @@ class RustLanguageClient extends AutoLanguageClient {
     clearIdeRustNotifications("ide-rust.langServerCommand")
 
     return logSuspiciousStdout(cp.spawn(languageServerCmd, {
-      env: await serverEnv(configToolchain()),
+      env: serverEnv(),
       shell: true,
       cwd: projectPath
     }))