I was hitting the same issue for a week.

Since today, I change the Xcode Version back to `Xcode 9.2` - and the problem was resolved.

It seems like this is a bug of `Xcode 9.3`, I just filed an issue to Apple yesterday. No reply has been received.

I had two versions of Xcode installed, and was experiencing this when using the Instruments associated with the oldest version of Xcode (9.4.1). 

I solved the issue by using the Instruments associated with the newest version of Xcode I had installed (10.0) 

I&#39;ve the below custom widget that make a `Switch` and reads its status (true/false)

Then I add this one to my main app widget (parent), how can I make the parent knows the value of the switch!

    import &#39;package:flutter/material.dart&#39;;
    
    class Switchy extends StatefulWidget{
      Switchy({Key key}) : super(key: key);
    
      @override
      State&lt;StatefulWidget&gt; createState() =&gt; new _SwitchyState();
      }
    
    class _SwitchyState extends State&lt;Switchy&gt; {
      var myvalue = true;
    
      void onchange(bool value) {
        setState(() {
          this.myvalue = value;      // I need the parent to receive this one!
          print(&#39;value is: $value&#39;);
        });
      }
    
      @override
      Widget build(BuildContext context) {
        return             
          new Card(
          child: new Container(
            child: new Row(
              mainAxisAlignment: MainAxisAlignment.end,
              children: &lt;Widget&gt;[
                new Text(&quot;Enable/Disable the app in the background&quot;,
                  textAlign: TextAlign.left,
                  textDirection: TextDirection.ltr,),
                new Switch(value: myvalue, onChanged: (bool value) =&gt; onchange(value)),
              ],
            ),
          ),
        );
      }
    }

In the `main.dart` (parent) file, I started with this:

    import &#39;widgets.dart&#39;;
    import &#39;package:flutter/material.dart&#39;;
    
    void main() =&gt; runApp(new MyApp());
    
    class MyApp extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return new MaterialApp(
          title: &#39;Flutter Demo&#39;,
          theme: new ThemeData(
            primarySwatch: Colors.deepOrange,
          ),
          home: new MyHomePage(title: &#39;My App settup&#39;),
        );
      }
    }
    
    class MyHomePage extends StatefulWidget {
      MyHomePage({Key key, this.title}) : super(key: key);
    
      final String title;
    
      @override
      _MyHomePageState createState() =&gt; new _MyHomePageState();
    }
    
    class _MyHomePageState extends State&lt;MyHomePage&gt; {
    
      Widget e = new Switchy();
      //...
    
    }

How to pass data from child widget to its parent

Updated answer (7/10/2021): For AWS CLI v1, do this:

```bash
export AWS_DEFAULT_PROFILE=user2
```

For AWS CLI v2, the following will work:

```bash
export AWS_PROFILE=user2
```

The full question is below for context:

----------

(1.) After successfully configuring a second profile for the AWS CLI, I unsuccessfully tried to set the profile to user2 in my bash session with the following command:

    export AWS_PROFILE=user2

... per the advice here: https://docs.aws.amazon.com/cli/latest/userguide/cli-multiple-profiles.html

(2.) The following command works: 

```bash
aws s3 ls --profile user2
```

So I know that the AWS CLI and the user2 profile are both working on my computer.

(3.) However, when I subsequently (that is, after entering &quot;export AWS_PROFILE=user2&quot;) try something like:

```bash
aws s3 ls
```

... AWS&#39;s response assumes that I want to query it as the default user (NOT user2)

(4.) So the only way I can use the user2 profile from the command line is by continuing to append &quot;--profile user2&quot; to every single command, which is tedious.


(5.)

```bash
echo $AWS_PROFILE
```

yields:

```bash
&gt;&gt; user2
```

, as expected.


Any idea what&#39;s going on here? I&#39;m sure I&#39;m making some dumb mistake somewhere.

How to temporarily switch profiles for AWS CLI?

I recently update my Xcode to version 9.3, so is instruments. After that, time profiler won&#39;t work anymore, it usually works fine before.

I tried to run it via Xcode, and I tried to run it manually. Doesn&#39;t work.
The life cycle row stuck in initializing, and I got a bunch of warnings complain about **the data volume is too high for a recording mode of &quot;immediate&quot; and some data had to be dropped to move forward**. 

Then I switch to delay mode, still got nothing. Then I create a simple new project, which should have &quot;little data volume&quot;, still got nothing.

I checked help, I googled, seems like no one has encountered this before. Does anyone have any clue about this?

![enter image description here][1]

  [1]: https://i.stack.imgur.com/gyGGq.png

Time profiler in instruments is not working

I recently update my Xcode to version 9.3, so is instruments. After that, time profiler won't work anymore, it usually works fine before.
I tried to run it via Xcode, and I tried to run it manually. Doesn't work.
The life cycle row stuck in initializing, and I got a bunch of warnings complain about the data volume is too high for a recording mode of "immediate" and some data had to be dropped to move forward.
Then I switch to delay mode, still got nothing. Then I create a simple new project, which should have "little data volume", still got nothing.
I checked help, I googled, seems like no one has encountered this before. Does anyone have any clue about this?
<img src="https://i.stack.imgur.com/gyGGq.png" alt="enter image description here">

How can I get the height of an **AppBar** in Flutter?&lt;br&gt;
I am using the MarialApp Widget (&#39;package:flutter/material.dart&#39;).&lt;br&gt;&lt;br&gt;
I have the height of my Context and would like to deduct the height of the appbar.

    final double height = MediaQuery.of(context).size.height;



How to get AppBar height in Flutter?

I am trying to add data using for loop in gridview but it is showing some error. Here is my code for component

    return new GridView.count(
        crossAxisCount: 2,
        padding: const EdgeInsets.all(10.0),
        crossAxisSpacing: 10.0,
        mainAxisSpacing: 10.0,
        children: &lt;Widget&gt;[getList()],
    );

getList() code

    List&lt;Widget&gt; getList() {
      List&lt;Widget&gt; childs = [];
      for (var i = 0; i &lt; 10; i++) {
        childs.add(new ListItem(&#39;abcd &#39; + $i));
      }
      return childs;
    }

But it is showing compile time error.

    The element type &#39;List&lt;widget&gt;&#39; can&#39;t be assigned to the list type &#39;Widget&#39;

the element type &#39;List&lt;widget&gt;&#39; can&#39;t be assigned to the list type &#39;Widget&#39;

I have a development pod that I connect to the my app locally using `:path =&gt; &#39;~/Projects/Swift/pod&#39;`. When I make changes inside the application code in that  development pod, this changes are not included after build. It&#39;s like I&#39;m build cached code, not my code changes. 

For include code changes into build I have to run the command &quot;Clean Build Folder&quot;, but after that build takes a very long time, for 10 minutes, which is not very productive. 

Literally, I comment on a line of code and wait 10 minutes to see the changes.

What is the problem?

I was trying to run &quot;pod install/pod update&quot; after any changes, but it has no effect.

How to rebuild development pod changes?

In Flutter i write simple dialog for loader during async task. when i touch outside dialog dismissed, How can I stop this behaviour ?

**Code**

      showDialog(
        context: context,
        builder: (_) =&gt; new Dialog(
              child: new Container(
                alignment: FractionalOffset.center,
                height: 80.0,
                padding: const EdgeInsets.all(20.0),
                child: new Row(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    new CircularProgressIndicator(),
                    new Padding(
                      padding: new EdgeInsets.only(left: 10.0),
                      child: new Text(&quot;Loading&quot;),
                    ),
                  ],
                ),
              ),
            ));

 Any help will be appreciated, thank you in advance.



Prevent dialog from closing on outside touch in Flutter

How could I add divider to list? I use Flutter for Android. I want to add a divider between each List item and I want to colorize the divider and add styles. 

I tried to add `new divider();` but I got errors. I also tried `return new divider();`.

Here is the screen shot of my app:

&lt;img src=&quot;https://i.stack.imgur.com/P7h8a.png&quot; width=&quot;300&quot; &gt;

And here is my code:

    import &#39;package:flutter/material.dart&#39;;
    import &#39;package:flutter/foundation.dart&#39;;
    
    void main() =&gt; runApp(const MyApp());
    
    class MyApp extends StatelessWidget {
      const MyApp();
    
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          theme: ThemeData(
              primarySwatch: Colors.purple,
    
              buttonTheme: const ButtonThemeData(
                textTheme: ButtonTextTheme.primary,
              )
          ),
          home: const MyHomePage(),
        );
      }
    }
    
    class Kitten {
      const Kitten({this.name, this.description, this.age, this.imageurl});
    
      final String name;
      final String description;
      final int age;
      final String imageurl;
    }
    
    final List&lt;Kitten&gt; _kittens = &lt;Kitten&gt;[
      Kitten(
          name: &quot;kitchen&quot;,
          description: &quot;mehraboon&quot;,
          age: 2,
          imageurl:
          &quot;https://images.pexels.com/photos/104827/cat-pet-animal-domestic- 
          104827.jpeg?auto=compress&amp;cs=tinysrgb&amp;dpr=2&amp;h=350&quot;,
      ),
      Kitten(
          name: &quot;garage&quot;,
          description: &quot;khashen&quot;,
          age: 1,
          imageurl:
          &quot;https://images.pexels.com/photos/4602/jumping-cute-playing-animals.jpg? 
          auto=compress&amp;cs=tinysrgb&amp;dpr=2&amp;h=350&quot;,
      ),
      Kitten(
          name: &quot;bedroom&quot;,
          description: &quot;khar zoor&quot;,
          age: 5,
          imageurl:
          &quot;https://images.pexels.com/photos/978555/pexels-photo-978555.jpeg? 
          auto=compress&amp;cs=tinysrgb&amp;dpr=2&amp;h=350&quot;,
      ),
      Kitten(
          name: &quot;living room&quot;,
          description: &quot;chorto&quot;,
          age: 3,
          imageurl:
          &quot;https://images.pexels.com/photos/209037/pexels-photo-209037.jpeg? 
          auto=compress&amp;cs=tinysrgb&amp;dpr=2&amp;h=350&quot;,
      ),
    ];
    
    class MyHomePage extends StatelessWidget {
      const MyHomePage({Key key}) : super(key: key);
    
      Widget _dialogBuilder(BuildContext context, Kitten kitten) {
        return SimpleDialog(contentPadding: EdgeInsets.zero, children: [
          Image.network(kitten.imageurl, fit: BoxFit.fill),
          Padding(
              padding: const EdgeInsets.all(16.0),
              child:
              Column(crossAxisAlignment: CrossAxisAlignment.stretch, children: [
                Text(kitten.name),
                Text(&#39;${kitten.age}&#39;),
                SizedBox(
                  height: 16.0,
                ),
                Text(kitten.description),
                Align(
                  alignment: Alignment.centerRight,
                  child: Wrap(
                    children: [
                      FlatButton(onPressed: () {}, child: const
                      Text(&quot;noooo!&quot;),color: Colors.red,),
                      Padding(padding: const EdgeInsets.all(2.0),),
                      RaisedButton(onPressed: () {}, child: const
                      Text(&quot;yesss!&quot;),color: Colors.green)
                    ],
                  ),
                )
              ]))
        ]);
      }
    
      Widget _listItemBuilder(BuildContext context, int index) {
        return new GestureDetector(
    
          onTap: () =&gt; showDialog(
              context: context,
              builder: (context) =&gt; _dialogBuilder(context, _kittens[index])),
          child:
          Container(
    
            padding: EdgeInsets.all( 16.0),
            alignment: Alignment.centerLeft,
            child: Text(_kittens[index].name,
                style: Theme.of(context).textTheme.headline),
    
          ),
    
    
        ) ;
    
      }
    
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(
            title: Text(&quot;Keys&quot;),
            centerTitle: true,
    
    
          ),
          body: ListView.builder(
            itemCount: _kittens.length,
            itemExtent: 60.0,
            itemBuilder: _listItemBuilder,
    
          ),
        );
      }
    }
     

Flutter : How can I add divider between each List Item in my code?

# My goal
I am trying to install Python 2.7.5 and 3.6.5 side-by-side on my MBP with with pyenv. 

# `pyenv` Installation
Following https://stackoverflow.com/questions/18671253/how-can-i-use-homebrew-to-install-both-python-2-and-3-on-mac , I tried:


    $ pyenv install 3.6.5

Which erred with:

    python-build: use openssl from homebrew
    python-build: use readline from homebrew
    Downloading Python-3.6.5.tar.xz...
    -&gt; https://www.python.org/ftp/python/3.6.5/Python-3.6.5.tar.xz
    Installing Python-3.6.5...
    python-build: use readline from homebrew
    
    BUILD FAILED (OS X 10.13.4 using python-build 20160602)
    
    Inspect or clean up the working tree at /var/folders/d0/t8d3jjp161g2dyrd4k67ypc80000gn/T/python-build.20180426091253.34709
    Results logged to /var/folders/d0/t8d3jjp161g2dyrd4k67ypc80000gn/T/python-build.20180426091253.34709.log
    
    Last 10 log lines:
      File &quot;/private/var/folders/d0/t8d3jjp161g2dyrd4k67ypc80000gn/T/python-build.20180426091253.34709/Python-3.6.5/Lib/ensurepip/__main__.py&quot;, line 5, in &lt;module&gt;
        sys.exit(ensurepip._main())
      File &quot;/private/var/folders/d0/t8d3jjp161g2dyrd4k67ypc80000gn/T/python-build.20180426091253.34709/Python-3.6.5/Lib/ensurepip/__init__.py&quot;, line 204, in _main
        default_pip=args.default_pip,
      File &quot;/private/var/folders/d0/t8d3jjp161g2dyrd4k67ypc80000gn/T/python-build.20180426091253.34709/Python-3.6.5/Lib/ensurepip/__init__.py&quot;, line 117, in _bootstrap
        return _run_pip(args + [p[0] for p in _PROJECTS], additional_paths)
      File &quot;/private/var/folders/d0/t8d3jjp161g2dyrd4k67ypc80000gn/T/python-build.20180426091253.34709/Python-3.6.5/Lib/ensurepip/__init__.py&quot;, line 27, in _run_pip
        import pip
    zipimport.ZipImportError: can&#39;t decompress data; zlib not available
    make: *** [install] Error 1

# What have I tried
* Installing zlib: `brew install zlib`

# My question
How can I install multiple Python environment with `pyenv` on MBP?

pyenv zlib error on MacOS:

Apple announced a new Dark Mode for Xcode 10. I&#39;ve downloaded the beta but now I can&#39;t find any option to turn it on. I&#39;m currently on macOS 10.13 High Sierra.

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/jtJOQ.png

How to enable Dark Mode for Xcode

What is &#39;Multi-cursor editing&#39; in Xcode 10 editor. (more information about the same is mentioned in [release notes][1] but unable to understand.)

How exactly does it work?


  [1]: https://download.developer.apple.com/Documentation/Xcode_10_beta_Release_Notes/Xcode_10_Beta_Release_Notes.pdf

Multi-cursor editing in Xcode 10

I have a very simple application with a single view, containing several UILabels. Upon running in Simulator, the Xcode console returns the error:

&gt; libMobileGestalt MobileGestalt.c:875: MGIsDeviceOneOfType is not supported on this platform.

The Simulator itself just shows a white screen. I&#39;ve also tried running it on a developer device with the same white screen. I&#39;ve searched documentation but can&#39;t find any reference to `MGIsDeviceOneOfType`.
The application is written in Swift in Xcode 10 beta on macOS 10.14. I am attempting to run it on the iPhone 7-X Simulators, as well as a development iPhone 7, all running the target software (12.0).


Xcode Error on Simulator: MGIsDeviceOneOfType is not supported on this platform

We&#39;re using React Native `0.59.10` and React-Redux `5.0.7`, and are experiencing a CPU-bound performance issue, in which our Redux actions are taking ~0.25s to complete.

We&#39;ve profiled using the Time Profiler configuration in Instruments, but none of our JS code is symbolicated.

Remotely debugging in Chrome seems to just debug the &quot;remote inspector&quot; page, which is entirely unhelpful.

Is there a way to build/attach a source map, or symbolicate the memory addresses seen below, to the JS function names/calls?

[![Instruments Callstack][1]][1]


  [1]: https://i.stack.imgur.com/HW82V.png

Content Type	Original Author	Original Content on Stackoverflow
Question	Carusd Ray	View Question on Stackoverflow
Solution 1 - Ios	suxinde2009	View Answer on Stackoverflow
Solution 2 - Ios	Marmoy	View Answer on Stackoverflow

Time profiler in instruments is not working

Ios Problem Overview

Ios Solutions

Solution 1 - Ios

Solution 2 - Ios

How to temporarily switch profiles for AWS CLI?

How to pass data from child widget to its parent

Attributions