Make pod install a long-running step. (#8999)

The very first time `pod install` is invoked, CocoaPods downloads the master spec repository, which takes quite a while. Before this change, the build appeared to have stalled. With this change, at least the spinner is moving.

Added `pod setup` to the install instructions for CocoaPods, so the spec repo is downloaded while setting up Flutter, instead of during the first build.

packages/flutter_tools/lib/src/base/process.dart

@@ -182,19 +182,36 @@ Future<Process> runDetached(List<String> cmd) {
 
 Future<RunResult> runAsync(List<String> cmd, {
   String workingDirectory,
-  bool allowReentrantFlutter: false
+  bool allowReentrantFlutter: false,
+  Map<String, String> environment
 }) async {
   _traceCommand(cmd, workingDirectory: workingDirectory);
   final ProcessResult results = await processManager.run(
     cmd,
     workingDirectory: workingDirectory,
-    environment: _environment(allowReentrantFlutter),
+    environment: _environment(allowReentrantFlutter, environment),
   );
   final RunResult runResults = new RunResult(results);
   printTrace(runResults.toString());
   return runResults;
 }
 
+Future<RunResult> runCheckedAsync(List<String> cmd, {
+  String workingDirectory,
+  bool allowReentrantFlutter: false,
+  Map<String, String> environment
+}) async {
+  final RunResult result = await runAsync(
+      cmd,
+      workingDirectory: workingDirectory,
+      allowReentrantFlutter: allowReentrantFlutter,
+      environment: environment
+  );
+  if (result.exitCode != 0)
+    throw 'Exit code ${result.exitCode} from: ${cmd.join(' ')}';
+  return result;
+}
+
 bool exitsHappy(List<String> cli) {
   _traceCommand(cli);
   try {

packages/flutter_tools/lib/src/commands/build_ios.dart

@@ -6,7 +6,6 @@ import 'dart:async';
 
 import '../application_package.dart';
 import '../base/common.dart';
-import '../base/logger.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
 import '../globals.dart';
@@ -64,8 +63,7 @@ class BuildIOSCommand extends BuildSubCommand {
     final String logTarget = forSimulator ? 'simulator' : 'device';
 
     final String typeName = artifacts.getEngineType(TargetPlatform.ios, getBuildMode());
-    final Status status = logger.startProgress('Building $app for $logTarget ($typeName)...',
-        expectSlowOperation: true);
+    printStatus('Building $app for $logTarget ($typeName)...');
     final XcodeBuildResult result = await buildXcodeProject(
       app: app,
       mode: getBuildMode(),
@@ -73,7 +71,6 @@ class BuildIOSCommand extends BuildSubCommand {
       buildForDevice: !forSimulator,
       codesign: shouldCodesign
     );
-    status.stop();
 
     if (!result.success) {
       await diagnoseXcodeBuildFailure(result);

packages/flutter_tools/lib/src/ios/ios_workflow.dart

@@ -185,13 +185,15 @@ class IOSWorkflow extends DoctorValidator implements Workflow {
           messages.add(new ValidationMessage.error(
             'CocoaPods not installed. To install:\n'
             'brew update\n'
-            'brew install cocoapods'
+            'brew install cocoapods\n'
+            'pod setup'
           ));
         } else {
           messages.add(new ValidationMessage.error(
             'CocoaPods out of date ($cocoaPodsMinimumVersion is required). To upgrade:\n'
             'brew update\n'
-            'brew upgrade cocoapods'
+            'brew upgrade cocoapods\n'
+            'pod setup'
           ));
         }
       }

packages/flutter_tools/lib/src/ios/mac.dart

@@ -11,6 +11,7 @@ import '../application_package.dart';
 import '../base/context.dart';
 import '../base/common.dart';
 import '../base/file_system.dart';
+import '../base/logger.dart';
 import '../base/io.dart';
 import '../base/platform.dart';
 import '../base/process.dart';
@@ -130,7 +131,7 @@ Future<XcodeBuildResult> buildXcodeProject({
   await _addServicesToBundle(appDirectory);
   writeFlutterPluginsList();
 
-  _runPodInstall(appDirectory, flutterFrameworkDir(mode));
+  await _runPodInstall(appDirectory, flutterFrameworkDir(mode));
 
   final List<String> commands = <String>[
     '/usr/bin/env',
@@ -170,11 +171,13 @@ Future<XcodeBuildResult> buildXcodeProject({
     );
   }
 
+  final Status status = logger.startProgress('Running Xcode build...', expectSlowOperation: true);
   final RunResult result = await runAsync(
     commands,
     workingDirectory: app.appDirectory,
     allowReentrantFlutter: true
   );
+  status.stop();
 
   if (result.exitCode != 0) {
     printStatus('Failed to build iOS app');
@@ -321,7 +324,7 @@ bool _checkXcodeVersion() {
   return true;
 }
 
-void _runPodInstall(Directory bundle, String engineDirectory)  {
+Future<Null> _runPodInstall(Directory bundle, String engineDirectory) async {
   if (fs.file(fs.path.join(bundle.path, 'Podfile')).existsSync()) {
     if (!doctor.iosWorkflow.cocoaPodsInstalledAndMeetsVersionCheck) {
       final String minimumVersion = doctor.iosWorkflow.cocoaPodsMinimumVersion;
@@ -329,11 +332,13 @@ void _runPodInstall(Directory bundle, String engineDirectory)  {
       return;
     }
     try {
-      runCheckedSync(
+      final Status status = logger.startProgress('Running pod install...', expectSlowOperation: true);
+      await runCheckedAsync(
           <String>['pod', 'install'],
           workingDirectory: bundle.path,
           environment: <String, String>{'FLUTTER_FRAMEWORK_DIR': engineDirectory},
       );
+      status.stop();
     } catch (e) {
       throwToolExit('Error running pod install: $e');
     }