From 297fa2ac62f5ca7864b2c54f334e5a389f9f6c9e Mon Sep 17 00:00:00 2001
From: Rich Chiodo <rchiodo@microsoft.com>
Date: Fri, 4 Oct 2019 10:16:44 -0700
Subject: [PATCH] Fix jupyter server startup hang when xeus-cling is installed

---
 news/2 Fixes/7569.md                       |  1 +
 src/client/common/process/pythonProcess.ts | 21 +++++++++++++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)
 create mode 100644 news/2 Fixes/7569.md

diff --git a/news/2 Fixes/7569.md b/news/2 Fixes/7569.md
new file mode 100644
index 000000000000..20e5e8a45853
--- /dev/null
+++ b/news/2 Fixes/7569.md	
@@ -0,0 +1 @@
+Fix jupyter server startup hang when xeus-cling kernel is installed.
diff --git a/src/client/common/process/pythonProcess.ts b/src/client/common/process/pythonProcess.ts
index 6030df4a6e11..9d7d15333768 100644
--- a/src/client/common/process/pythonProcess.ts
+++ b/src/client/common/process/pythonProcess.ts
@@ -1,17 +1,26 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
-
 import { injectable } from 'inversify';
 import * as path from 'path';
+
 import { IServiceContainer } from '../../ioc/types';
 import { EXTENSION_ROOT_DIR } from '../constants';
 import { ErrorUtils } from '../errors/errorUtils';
 import { ModuleNotInstalledError } from '../errors/moduleNotInstalledError';
 import { traceError } from '../logger';
 import { IFileSystem } from '../platform/types';
+import { waitForPromise } from '../utils/async';
 import { Architecture } from '../utils/platform';
 import { parsePythonVersion } from '../utils/version';
-import { ExecutionResult, InterpreterInfomation, IProcessService, IPythonExecutionService, ObservableExecutionResult, PythonVersionInfo, SpawnOptions } from './types';
+import {
+    ExecutionResult,
+    InterpreterInfomation,
+    IProcessService,
+    IPythonExecutionService,
+    ObservableExecutionResult,
+    PythonVersionInfo,
+    SpawnOptions
+} from './types';
 
 @injectable()
 export class PythonExecutionService implements IPythonExecutionService {
@@ -28,8 +37,12 @@ export class PythonExecutionService implements IPythonExecutionService {
     public async getInterpreterInformation(): Promise<InterpreterInfomation | undefined> {
         const file = path.join(EXTENSION_ROOT_DIR, 'pythonFiles', 'interpreterInfo.py');
         try {
-            const jsonValue = await this.procService.exec(this.pythonPath, [file], { mergeStdOutErr: true })
-                .then(output => output.stdout.trim());
+            // Sometimes the python path isn't valid, timeout if that's the case.
+            // See these two bugs:
+            // https://github.com/microsoft/vscode-python/issues/7569
+            // https://github.com/microsoft/vscode-python/issues/7760
+            const jsonValue = await waitForPromise(this.procService.exec(this.pythonPath, [file], { mergeStdOutErr: true }), 5000)
+                .then(output => output ? output.stdout.trim() : '--timed out--'); // --timed out-- should cause an exception
 
             let json: { versionInfo: PythonVersionInfo; sysPrefix: string; sysVersion: string; is64Bit: boolean };
             try {