Issue 1:
'flutter doctor' worked correctly it suggested I update so then

I ran 'flutter upgrade' as well as updating my macos and xcode. Then ran xcode and which installed additional updates.

Karls-MBP-2:~ karllilley$ flutter doctor -v

[✓] Flutter (Channel beta, v0.2.3, on Mac OS X 10.13.4 17E199, locale en-US)

• Flutter version 0.2.3 at /Users/karllilley/flutter

• Framework revision 5a58b36 (3 weeks ago), 2018-03-13 13:20:13 -0700

• Engine revision e61bb9a

• Dart version 2.0.0-dev.35.flutter-290c576264

Oops; flutter has exited unexpectedly.
Sending crash report to Google.
Crash report sent (report ID: 11ccd05f01dbb253)
Unhandled exception:
NoSuchMethodError: The method 'run' was called on null.
Receiver: null
Tried calling: run(Instance(length:2) of '_GrowableList', environment: null, workingDirectory: null)
#0 Object.noSuchMethod (dart:core-patch/dart:core/object_patch.dart:46)
#1 runAsync (package:flutter_tools/src/base/process.dart:227)
<asynchronous suspension>
#2 IOSWorkflow.macDevMode (package:flutter_tools/src/ios/ios_workflow.dart:45)
<asynchronous suspension>
#3 IOSWorkflow.validate (package:flutter_tools/src/ios/ios_workflow.dart:90)
<asynchronous suspension>
#4 Doctor.startValidatorTasks (package:flutter_tools/src/doctor.dart:71)
#5 Doctor.diagnose (package:flutter_tools/src/doctor.dart:128)
<asynchronous suspension>
#6 _doctorText.<anonymous closure> (package:flutter_tools/runner.dart:237)
#7 AppContext._run (package:flutter_tools/src/base/context.dart:76)
<asynchronous suspension>
#8 AppContext.runInZone.<anonymous closure> (package:flutter_tools/src/base/context.dart:66)
#9 _rootRun (dart:async/zone.dart:1126)
#10 _CustomZone.run (dart:async/zone.dart:1023)
#11 runZoned (dart:async/zone.dart:1501)
#12 AppContext.runInZone (package:flutter_tools/src/base/context.dart:65)
#13 _doctorText (package:flutter_tools/runner.dart:237)
<asynchronous suspension>
#14 _createLocalCrashReport (package:flutter_tools/runner.dart:212)
<asynchronous suspension>
#15 _handleToolError (package:flutter_tools/runner.dart:167)
<asynchronous suspension>
#16 run.<anonymous closure> (package:flutter_tools/runner.dart:94)
<asynchronous suspension>
#17 AppContext._run (package:flutter_tools/src/base/context.dart:76)
<asynchronous suspension>
#18 AppContext.runInZone.<anonymous closure> (package:flutter_tools/src/base/context.dart:66)
#19 _rootRun (dart:async/zone.dart:1126)
#20 _CustomZone.run (dart:async/zone.dart:1023)
#21 runZoned (dart:async/zone.dart:1501)
#22 AppContext.runInZone (package:flutter_tools/src/base/context.dart:65)
#23 run (package:flutter_tools/runner.dart:61)
<asynchronous suspension>
#24 main (package:flutter_tools/executable.dart:48)
<asynchronous suspension>
#25 main (file:///Users/karllilley/flutter/packages/flutter_tools/bin/flutter_tools.dart:16)
#26 _startIsolate.<anonymous closure> (dart:isolate-patch/dart:isolate/isolate_patch.dart:277)
#27 _RawReceivePortImpl._handleMessage (dart:isolate-patch/dart:isolate/isolate_patch.dart:165)

Issue 2:
Our console output when running xCode builds is very noisy and hard to read. We heard very good things about https://github.com/supermarin/xcpretty from another team that runs xCode builds, so would be good to give that a try for Flutter.