So your app works, you just don't get debug output do I understand this right?

@escamoteur Correct.

Thanks for filing this @stx. This is related to #40448. This isn't a regression in Flutter, but rather that something changed in iOS 13 that we are no longer able to read logs. I worked around this in that issue by using mDNS to discover the app observatory, but we still need to fix the lack of logs.

@christopherfujino Thanks for looking into it. The app observatory logs are nearly unusable for us because they spam frames and we're animating constantly. Effectively, this means that we don't get to do iOS debugging until this is fixed.

The title of this issue does not explicitly state that the problem occurs only with physical devices. In my case it happens only with physical iOS devices with iOS 13 but not with a iOS simulator with iOS 13.

@stx is this correct? It only happens on a physical device?

After switching my devices to iOS 13, also hit this issue, and can confirm that logs still work with simulator (XCode beta, simulator devices running iOS 13, string from simulator About page: Version 11.0 (SimulatorApp-912.1 SimulatorKit-570.3 CoreSimulator-681.5.1))

Also, just in case, if I run app from XCode, logs are shown.

$ flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel master, v1.10.6-pre.29, on Mac OS X 10.14.6 18G95, locale en-ES)
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)

[✓] Xcode - develop for iOS and macOS (Xcode 11.0)

[!] Android Studio

✗ Flutter plugin not installed; this adds Flutter specific functionality.

✗ Dart plugin not installed; this adds Dart specific functionality.

[!] Android Studio (version 3.3)

✗ Flutter plugin not installed; this adds Flutter specific functionality.

✗ Dart plugin not installed; this adds Dart specific functionality.

[✓] VS Code (version 1.38.1)

[✓] Connected device (2 available)
! Doctor found issues in 2 categories.

@escamoteur Just tested this and can also confirm that logs work on the iOS 13 simulator.

This is also blocking me. Is there a workaround?

@RyanRamchandar none that I know of at this time, other than using a simulator.

No output from print()

(Adding this comment here because it was hard for me to search for. Hope it helps others.)

I'm developing an app that needs to use the camera as a qrcode scanner. Makes it a bit rough to test it when there is no way to do scanning. ;-) I was in the middle of developing a new feature when I stepped way from the project for a few weeks to work on the backend, and then came back to this mess from ios13. lol.

Seeing a lot of this message in the Xcode console. Maybe related.

[] nw_connection_receive_internal_block_invoke [C1] Receive reply failed with error "Operation canceled"

@RyanRamchandar The workaround for me right now has to been to just set breakpoints in the debugger. Kind of a pain when you just want to print something out, but shrug... it works.

@joaowd this has been fixed on version 1.10.15. You can get the fix by switching to the dev channel. This will be in the next stable release of flutter.

This logger works:

import 'dart:developer' as logger;

logger.log();

This logger works:

import 'dart:developer' as logger;

logger.log();

Can confirm! That´s nice!

why does

import 'dart:developer' as logger;

logger.log();

work, but not print(). Can anyone explain?

@vagrantrobbie output from print() is written to the apps stdout stream and read via the devices logs (which is what is failing here). dart:developer is instead sent as messages over the VM service (this is the service that the IDE connects to in order to communiticate with the VM - for example to control debugging). The IDEs need to have specific handling for these messages (added fairly recently in the VS Code extension).

It is already working on the dev channel

Same problem here (more info);

I have 2 iPhones (iPhone 7 and 11)
iPhone 7 (13.3) this device works with the debug window
iPhone 11 (13.3) this device does not work with the debug window
Flutter: 1.12.13+hotfix.5. this is sable release

Wants happening with iPhone 11 ???

I had met the same problem, but I worked in Windows.I just upgrade my flutter sdk without anything else.

@joaowd this has been fixed on version 1.10.15. You can get the fix by switching to the dev channel. This will be in the next stable release of flutter.

@joaowd is it solved? it happens again in 1.12.13+hotfix9...

@joaowd this has been fixed on version 1.10.15. You can get the fix by switching to the dev channel. This will be in the next stable release of flutter.

@joaowd is it solved? it happens again in 1.12.13+hotfix9...

Yes!

Same problem here (more info);

I have 2 iPhones (iPhone 7 and 11)
iPhone 7 (13.3) this device works with the debug window
iPhone 11 (13.3) this device does not work with the debug window
Flutter: 1.12.13+hotfix.5. this is sable release

Wants happening with iPhone 11 ???

I have met the same question.
iPhone 11 pro max could't work.

working with v1.17.1

NOT working with v1.17.1
iPhone XR 13.4.1
And, execution doesn't stop at breakpoints on first run. It works after I do a refresh.

Edit: Apologies for the false alarm. It turns out flutter somehow couldn't compile my latest code (the code with prints) and that's why I didn't see the logs. This was completely different issue

Working for me. iPhone 11 13.4.1. 🤷

I recently upgrade to the latest on the production branch and it is not working for me either now.

logger.log() does nothing as well.

Mine is not working
(Channel stable, v1.17.1, on Mac OS X 10.15.4 19E2269)
(Physical iOS 13 device, iPhone X)

using latest master branch and still not working

[✓] Flutter (Channel master, 1.19.0-2.0.pre.143, on Mac OS X 10.15.4 19E287, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
[✓] Xcode - develop for iOS and macOS (Xcode 11.4.1)
[✓] Android Studio (version 3.6)

tested on iPhone 6S iOS version 13.3.1

edit: i can use print() and somehow its the only thing that appeared inside my debug log, but the other debug message & exceptions did not appear

The only way it shows up is if you run the Debug tool rather then going "flutter run" in Visual Studio Code

I'm using 1.17.5 and also don't see any plugin outputs from Swift (using print or NSLog) when starting the app from Flutter. Neither in the debug console in VSCode, in the console app or in Xcode. I see them if I run the iOS example app in Xcode. I'm using the simulator.

This is one of the biggest flaws of dart/flutter. Always I have to use dart devtools to see the console outputs. Also I'm heavily using generators and I have to use terminal to see the build-runner exceptions!!!

P.S I'm a windows user

can we please fix this

This is a closed issue. If you are seeing a problem, please file a new GitHub issue and completely fill out the template so we know what version you're on and can investigate or duplicate to an open issue. Sometimes we investigate this complaint and the app isn't even running when people think it is due to a crash on launch.

There are already several open issues tracking various manifestations of this like #44717 and #44718.

This should be fixed as of #66399.