Revert "Write the Ruby environment information into a temporary file"

src/ruby.ts

@@ -1,6 +1,5 @@
 import path from "path";
 import fs from "fs/promises";
-import os from "os";
 
 import * as vscode from "vscode";
 
@@ -171,19 +170,11 @@ export class Ruby {
   private async activate(ruby: string) {
     let command = this.shell ? `${this.shell} -ic '` : "";
 
-    // Certain shell plugins take over standard pipes like `stderr` and cause activation issues. To get around tools
-    // that do that, we use a temporary file to write the environment information from Ruby and then read it in NodeJS
-    // to apply the right environment variables
-    const tmpFilePath = path.join(
-      os.tmpdir(),
-      `ruby_lsp_${path.basename(this.workingFolderPath)}`,
-    );
-
     // The Ruby activation script is intentionally written as an array that gets joined into a one liner because some
     // terminals cannot handle line breaks. Do not switch this to a multiline string or that will break activation for
     // those terminals
     const script = [
-      `File.write(\\"${tmpFilePath}\\", `,
+      "STDERR.printf(%{RUBY_ENV_ACTIVATE%sRUBY_ENV_ACTIVATE}, ",
       "JSON.dump({ env: ENV.to_h, ruby_version: RUBY_VERSION, yjit: defined?(RubyVM::YJIT) }))",
     ].join("");
 
@@ -197,19 +188,16 @@ export class Ruby {
       `Trying to activate Ruby environment with command: ${command} inside directory: ${this.cwd}`,
     );
 
-    try {
-      await asyncExec(command, { cwd: this.cwd });
-      const envJson = await fs.readFile(tmpFilePath, "utf8");
-      const rubyInfo = JSON.parse(envJson);
+    const result = await asyncExec(command, { cwd: this.cwd });
+    const rubyInfoJson = /RUBY_ENV_ACTIVATE(.*)RUBY_ENV_ACTIVATE/.exec(
+      result.stderr,
+    )![1];
 
-      this._env = rubyInfo.env;
-      this.rubyVersion = rubyInfo.ruby_version;
-      this.yjitEnabled = rubyInfo.yjit === "constant";
-    } catch (error: any) {
-      // Ensure we cleanup the temp file even if we failed to activate
-      await fs.rm(tmpFilePath);
-      throw error;
-    }
+    const rubyInfo = JSON.parse(rubyInfoJson);
+
+    this._env = rubyInfo.env;
+    this.rubyVersion = rubyInfo.ruby_version;
+    this.yjitEnabled = rubyInfo.yjit === "constant";
   }
 
   // Fetch information related to the Ruby version. This can only be invoked after activation, so that `rubyVersion` is