Infinite Measure Looping on iOS

[JohnTraDolta]

Description

I was upgrading our app to dotnet 10 and after testing on iOS, the app froze a lot of places, with no errors reported or anything.

After some digging i found that with some "magic" configuration (eg. label with font size 18) the app got stuck in some infinite measure loop.

I have tested with 10.0.0, 10.0.10, 10.0.11, 10.0.20, 10.0.30, 10.0.31 and 10.0.40

We have decided to pause our .net 10 upgrade until this is fixed

Steps to Reproduce

1. pull the code from the repo, run the code on iOS
2. press one of the 3 examples and wait for the quick and dirty loop detector to stop the loop (stopping after 500 size changed)
3. The app is unresponsive while the loop is running.

Link to public reproduction project repository

https://github.com/JohnTraDolta/MauiInfiniteMeasureLoopingBug

Version with bug

10.0.40

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

9.0.100 SR10

Affected platforms

iOS

Affected platform versions

iOS 26.1

Did you find any workaround?

Nothing i recommend, but changing Label font size, setting fixed height on labels. Not using GridLength.Auto.

Relevant log output

[JohnTraDolta]

I have made the repo public, sorry for the failed run

[dartasen]

May be fixed by #34024

[JohnTraDolta]

@dartasen can i help with testing this in any way?

[zwikk]

This might be the reason our app in production is seeing a huge amount of App is hanging issues in our Sentry log.

[dartasen]

@dartasen can i help with testing this in any way?

You might be able to test out a nightly build once the pipeline is successful to confirm the fix does work for you as well

EDIT: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_apis/build/builds/1292874/artifacts?artifactName=PackageArtifacts&api-version=7.1&%24format=zip => You can download PackageArtifacts.zip. If you create a local repo nuget and copy paste all the .nupkg inside the folder, you'll be able to test it by setting your MauiVersion to 10.0.50-ci.pr34024.26112.58

[JohnTraDolta]

@dartasen I can confirm that using MauiViersion 10.0.50-ci.pr34024.26112.58 does fix the issues reported in this report

[dartasen]

@dartasen I can confirm that using MauiViersion 10.0.50-ci.pr34024.26112.58 does fix the issues reported in this report

Thank's for testing this out !

@PureWeen

[LogishaSelvarajSF4525]

This issue has been validated in Visual Studio Code 1.109.3 with MAUI versions 9.0.100, 9.0.120, 10.0.0, 10.0.10, 10.0.30, 10.0.31 and 10.0.40. It can be reproduced from .NET10 on iOS(18.4, 26.0 & 26.1) platform.