fix microsoft#1005

Author: DonJayamanne

src/client/debugger/DebugClients/LocalDebugClient.ts

@@ -96,6 +96,11 @@ export class LocalDebugClient extends DebugClient {
  newEnvVars['PYTHONIOENCODING'] = 'UTF-8';
  process.env['PYTHONIOENCODING'] = 'UTF-8';
  }
+ if (!environmentVariables.hasOwnProperty('PYTHONUNBUFFERED')) {
+ environmentVariables['PYTHONUNBUFFERED'] = '1';
+ newEnvVars['PYTHONUNBUFFERED'] = '1';
+ process.env['PYTHONUNBUFFERED'] = '1';
+ }
  let ptVSToolsFilePath = this.getPTVSToolsFilePath();
  let launcherArgs = this.buildLauncherArguments();