I found this solution on stackoverflow and it worked for me

1-) cd ios 2-) rm -rf Podfile.lock 3-) rm -rf Pods 4-) pod install

works for me

@carloslibardo Thanks for testing this out. I tried to analyse the issue and I get this log on running your second example

 [Presentation] Attempt to present <RCTModalHostViewController: 0x7fd1a00abb20> on <RCTModalHostViewController: 0x7fd1a04137e0> (from <RCTModalHostViewController: 0x7fd1a04137e0>) whose view is not in the window hierarchy.

I think it tries to open the second modal before the first one is completely dismissed and there's where it breaks. Changing the above code to something like below works.

 <Modal
        visible={currentModal === 'modal1'}
        transparent
        onDismiss={() => {
          setCurrentModal('modal2');
        }}>
          <Button
            title="111"
            onPress={() => {
              setCurrentModal('dummyState');
            }}
          />
      <Modal visible={currentModal === 'modal2'} transparent>
          <Button
            title="button 2"
            onPress={() => {
              setCurrentModal('modal3');
            }}
          />
      </Modal>

I'll try to find a solution!

Same issue exists. The API call is working in a real device, but not in the emulator.

Now, my concern is, Should I worry that it doesn't work on emulator? It will be good if someone can answer this question, so that I can work with the real device until this issue is sorted out.

Same issue exists. The API call is working in a real device, but not in the emulator.

Now, my concern is, Should I worry that it doesn't work on emulator? It will be good if someone can answer this question, so that I can work with the real device until this issue is sorted out.

Description

I want to create a new project using this command :

`npx react-native init project-name but it freezes on this line :

⸨⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⸩ ⠇ rollbackFailedOptional: verb npm-session 08fef662d42ce334

I've reinstalled node,npm but nothing has changed.

To verify if the problem is related to npx or no, I tried to run npx create-react-app project-name and it works very well.

React Native version:

I tried to run npx react-native info but it displays :

⸨⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⠂⸩ ⠇ rollbackFailedOptional: verb npm-session ba05e90f993d0941

Expected Results

Created react-native project.

Snack, code example, screenshot, or link to a repository:

<!-- Ask a question or share feedback about the React 18 release here. -->

yarn run v1.22.5
$ react-scripts start

There might be a problem with the project dependency tree.
It is likely not a bug in Create React App, but something you need to fix locally.

The react-scripts package provided by Create React App requires a dependency:

  "babel-jest": "^26.6.0"

Don't try to install it manually: your package manager does it automatically.
However, a different version of babel-jest was detected higher up in 
the tree:

  C:\Users\UNION\node_modules\babel-jest (version: 27.0.2)

Manually installing incompatible versions is known to cause hard-to-debug issues.

If you would prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That will permanently disable this message but you might encounter other issues.

To fix the dependency tree, try following the steps below in the exact order:

  1. Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
  2. Delete node_modules in your project folder.
  3. Remove "babel-jest" from dependencies and/or devDependencies in 
the package.json file in your project folder.
  4. Run npm install or yarn, depending on the package manager you use.

In most cases, this should be enough to fix the problem.
If this has not helped, there are a few other things you can try:    

  5. If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.
     This may help because npm has known issues with package hoisting which may get resolved in future versions.

  6. Check if C:\Users\UNION\node_modules\babel-jest is outside your 
project directory.
     For example, you might have accidentally installed something in 
your home folder.

  7. Try running npm ls babel-jest in your project folder.
     This will tell you which other package (apart from the expected 
react-scripts) installed babel-jest.

If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file 
in your project.
That would permanently disable this preflight check in case you want 
to proceed anyway.

P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command. 



- I'm not able to solve this issue, I did tried the following steps but it seems like I'm not getting this? Please give some suggestions, so that i could work on my project smoothly.

Support requests filed as GitHub issues often go unanswered. We want you to find the answer you're looking for, so we suggest the following alternatives:

Coding Questions If you have a coding question related to React and React DOM, it might be better suited for Stack Overflow. It's a great place to browse through frequent questions about using React, as well as ask for help with specific questions.

https://stackoverflow.com/questions/tagged/react

Talk to other React developers There are many online forums which are a great place for discussion about best practices and application architecture as well as the future of React.

https://reactjs.org/community/support.html

<!-- Ask a question or share feedback about the React 18 release here. -->

yarn run v1.22.5
$ react-scripts start

There might be a problem with the project dependency tree.
It is likely not a bug in Create React App, but something you need to fix locally.

The react-scripts package provided by Create React App requires a dependency:

  "babel-jest": "^26.6.0"

Don't try to install it manually: your package manager does it automatically.
However, a different version of babel-jest was detected higher up in 
the tree:

  C:\Users\UNION\node_modules\babel-jest (version: 27.0.2)

Manually installing incompatible versions is known to cause hard-to-debug issues.

If you would prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That will permanently disable this message but you might encounter other issues.

To fix the dependency tree, try following the steps below in the exact order:

  1. Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
  2. Delete node_modules in your project folder.
  3. Remove "babel-jest" from dependencies and/or devDependencies in 
the package.json file in your project folder.
  4. Run npm install or yarn, depending on the package manager you use.

In most cases, this should be enough to fix the problem.
If this has not helped, there are a few other things you can try:    

  5. If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.
     This may help because npm has known issues with package hoisting which may get resolved in future versions.

  6. Check if C:\Users\UNION\node_modules\babel-jest is outside your 
project directory.
     For example, you might have accidentally installed something in 
your home folder.

  7. Try running npm ls babel-jest in your project folder.
     This will tell you which other package (apart from the expected 
react-scripts) installed babel-jest.

If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file 
in your project.
That would permanently disable this preflight check in case you want 
to proceed anyway.

P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command. 



- I'm not able to solve this issue, I did tried the following steps but it seems like I'm not getting this? Please give some suggestions, so that i could work on my project smoothly.

Raised in the wrong project... will raise in react project.

Hi,

It seems that there is a memory leak issue when using the set state hook lambda syntax, and setting the state to the previous state. The set state lambda in this scenario seems to be retained and never garbage collected.

Please ignore the contrived example, it's intentionally whittled down to the exact issue. It's quite a common requirement in our application to subscribe to an rxjs observable in a useEffect hook, then update some state when events are received (but the data received might not always result in a state change). The lambda syntax is required in the set state call because current state would otherwise always be the default state due to the closure around it in the useEffect hook. Even if there was another way to do it to avoid the issue, it's still a surprising behaviour and makes it harder to fall into the 'pit of success'.

Reproduction below:

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Memory leak repro</title>
    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>

    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
  </head>
  <body>
    <div id="root"></div>
    <script type="text/babel">
        function App() {
          const [someState, setSomeState] = React.useState(false);
          React.useEffect(() => {
             const interval = setInterval(() => {
               const a = []; 
               for (var i = 0; i < 1000; i++) {
                 a.push({}); //produce lots of garbage objects to make the leak easier to see
               }
               // memory leak when setting state to previous state
               // set state lambda is not garbage collected and retained along with all of its captured closures
               setSomeState(state => a.length > 0 ? state : !state);

               // no memory leak when setting state to something other than previous state
               // set state lambda (and it's closures) are garbage collected as expected
               // setSomeState(state => a.length == 0 ? state : !state);
              }, 100);
             return () => clearInterval(interval);
          }, []);
          return <div>Test Memory Leak</div>;
      }


      ReactDOM.render(
        <App/>,
        document.getElementById('root')
      );

    </script>
  </body>
</html>

The best memory profiler to see this is the 'Allocation instrumentation on timeline' mode in chrome devtools.

I have confirmed this also happens using production / minified bundles so it's not a dev build issue.

Right now as a workaround I need to use 'hacks' like useRef and forceUpdate implementations which is a real shame so keen to see this fixed.

Many thanks!

Hi,

It seems that there is a memory leak issue when using the set state hook lambda syntax, and setting the state to the previous state. The set state lambda in this scenario seems to be retained and never garbage collected.

Please ignore the contrived example, it's intentionally whittled down to the exact issue. It's quite a common requirement in our application to subscribe to an rxjs observable in a useEffect hook, then update some state when events are received (but the data received might not always result in a state change). The lambda syntax is required in the set state call because current state would otherwise always be the default state due to the closure around it in the useEffect hook. Even if there was another way to do it to avoid the issue, it's still a surprising behaviour and makes it harder to fall into the 'pit of success'.

Reproduction below:

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Memory leak repro</title>
    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>

    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
  </head>
  <body>
    <div id="root"></div>
    <script type="text/babel">
        function App() {
          const [someState, setSomeState] = React.useState(false);
          React.useEffect(() => {
             const interval = setInterval(() => {
               const a = []; 
               for (var i = 0; i < 1000; i++) {
                 a.push({}); //produce lots of garbage objects to make the leak easier to see
               }
               // memory leak when setting state to previous state
               // set state lambda is not garbage collected and retained along with all of its captured closures
               setSomeState(state => a.length > 0 ? state : !state);

               // no memory leak when setting state to something other than previous state
               // set state lambda (and it's closures) are garbage collected as expected
               // setSomeState(state => a.length == 0 ? state : !state);
              }, 100);
             return () => clearInterval(interval);
          }, []);
          return <div>Test Memory Leak</div>;
      }


      ReactDOM.render(
        <App/>,
        document.getElementById('root')
      );

    </script>
  </body>
</html>

The best memory profiler to see this is the 'Allocation instrumentation on timeline' mode in chrome devtools.

I have confirmed this also happens using production / minified bundles so it's not a dev build issue.

Right now as a workaround I need to use 'hacks' like useRef and forceUpdate implementations which is a real shame so keen to see this fixed.

Many thanks!

The main situation where I'm bumping up against this limitation is when using Map and Set data structures for my state, and using something like iter-tools to iterate over Map.entries() to generate my elements. Having to materialise all of my Iterables into Arrays makes the JSX quite a bit more cluttered.

Same issue here. Following...

Does a React Dev Tools guide exist with examples for different scenarios, breaking changes, when the wrapping colored box appears, the colors meaning ?

Found this but it's back from 2014: https://reactjs.org/blog/2014/01/02/react-chrome-developer-tools.html

While searching on the wild I have seen different examples that when tested on my end show a different result from the React Dev tools extension perspective which generates confusion.

Does this guide exist ? If not, will it be created?

Best Regards

Still broken on React Native 0.64. This is a pretty big issue. No solution worked for me other than removing the custom font.

Same error logs here with XCode 13.0 beta and 0.65-rc.2 referenced above ^

XCode 12.5 builds fine on both 0.64.2 and 0.65.0-rc.2

I'm on macOS Monterey 12.0 Beta too

got this when testing my app on android 11 beta.

android.webkit.WebViewFactory$MissingWebViewPackageException: Failed to load WebView provider: No WebView installed
    at android.webkit.WebViewFactory.getWebViewContextAndSetProvider(WebViewFactory.java:366)
    at android.webkit.WebViewFactory.getProviderClass(WebViewFactory.java:431)
    at android.webkit.WebViewFactory.getProvider(WebViewFactory.java:286)
    at android.webkit.CookieManager.getInstance(CookieManager.java:50)
    at com.facebook.react.modules.network.c.i(ForwardingCookieHandler.java:3)
    at com.facebook.react.modules.network.c.get(ForwardingCookieHandler.java:1)
    at okhttp3.JavaNetCookieJar.loadForRequest(JavaNetCookieJar.java:2)
    at com.facebook.react.modules.network.l.loadForRequest(ReactCookieJarContainer.java:2)
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:17)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:10)
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:9)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:10)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:1)
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:13)
    at okhttp3.RealCall$AsyncCall.execute(RealCall.java:2)
    at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:3)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.lang.Thread.run(Thread.java:920)

android.util.AndroidRuntimeException: android.webkit.WebViewFactory$MissingWebViewPackageException: Failed to load WebView provider: No WebView installed
    at android.webkit.WebViewFactory.getProviderClass(WebViewFactory.java:470)
    at android.webkit.WebViewFactory.getProvider(WebViewFactory.java:286)
    at android.webkit.CookieManager.getInstance(CookieManager.java:50)
    at com.facebook.react.modules.network.c.i(ForwardingCookieHandler.java:3)
    at com.facebook.react.modules.network.c.get(ForwardingCookieHandler.java:1)
    at okhttp3.JavaNetCookieJar.loadForRequest(JavaNetCookieJar.java:2)
    at com.facebook.react.modules.network.l.loadForRequest(ReactCookieJarContainer.java:2)
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:17)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:10)
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:9)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:10)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:1)
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:13)
    at okhttp3.RealCall$AsyncCall.execute(RealCall.java:2)
    at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:3)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.lang.Thread.run(Thread.java:920)

android.util.AndroidRuntimeException: android.util.AndroidRuntimeException: android.webkit.WebViewFactory$MissingWebViewPackageException: Failed to load WebView provider: No WebView installed
    at android.webkit.WebViewFactory.getProvider(WebViewFactory.java:301)
    at android.webkit.CookieManager.getInstance(CookieManager.java:50)
    at com.facebook.react.modules.network.c.i(ForwardingCookieHandler.java:3)
    at com.facebook.react.modules.network.c.get(ForwardingCookieHandler.java:1)
    at okhttp3.JavaNetCookieJar.loadForRequest(JavaNetCookieJar.java:2)
    at com.facebook.react.modules.network.l.loadForRequest(ReactCookieJarContainer.java:2)
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:17)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:10)
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:9)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:10)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:1)
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:13)
    at okhttp3.RealCall$AsyncCall.execute(RealCall.java:2)
    at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:3)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.lang.Thread.run(Thread.java:920)

Solution above works partly, only with deactivated CORS (for me) Do u have any ideas, how to allow using of devtools with enabled CORS?

I think Facebook need to handle this and generate GUID under the hood , cause they changed for to htmlFor so it means do it in react way

It took you guys almost one year to fix this regression when we developed native version of our application. No wonder people are leaving React Native in droves.

@Base29 My podfile changed to this which yours has commented out

require_relative '../node_modules/react-native/scripts/autolink-ios'

Not sure if that's the cause

flushSync is not a solution I had considered or was aware of, thanks for the pointer! I think it will serve my needs well enough, though it seems a bit heavy-handed to force the update to happen synchronously. Would an async version be possible? I reckon that on its own would cover most of the need, since the tools available for selecting and passing around state are already pretty good.

// Asynchronous version of flushSync. Not sure about the name. awaitFlush() perhaps?
await flushAsync(() => {
  setTabVisible(true)
}) // flushes DOM update
tabRef.current.scrollIntoView(); // updated by this point

The above suggestion is bare-bones, but I think you could do quite a lot with it. As an example:

function usePromiseReducer(reducer, initialState, initializer) {
  const [state, dispatch] = useReducer(reducer, initialState, initializer);
  const ref = useRef(state);

  // Keep track of the committed state. Layout effects happen before flushAsync resolves.
  useLayoutEffect(() => {
    ref.current = state;
  });

  const wrappedDispatch = useCallback(async (action) => {
    await flushAsync(() => dispatch(action));
    // Return the latest state, whether it was updated or not.
    // The reducer may have processed multiple actions before we get here.
    return ref.current;
  }, [dispatch]);

  return [state, wrappedDispatch];
}

Can possible add conditional checking (&&) at the place of null event.

Hi @timdorr

Can you reopen this issue? Since I have another question related to this.

Hi @myNameIsDu,

Thanks for the answer but can you elaborate more?

Here is an example of the same thing but in react-route@5. Its behavior does not look the same as v6.

https://codesandbox.io/s/react-router-v52-redirect-89rxe?file=/example.js

Base commit: 52a9fed3dfad55f2e122ea77134cc58d3a4e588d

So what the hell shall we do? :/ It's 2021 for God's sake

I ran a build on a ReactJS site. The website shows up on desktop perfectly fine but on mobile I am getting a blank white screen.

Thinking that I could easily solve this by solving all the "warnings" did nothing to fix it.

I was not able to locate the reason for this.

How can one diagnose an issue such as this when there is no F12/developer tools on mobile safari/chrome?

Please help.