Failure during CLI build after VS Upgrade

[divil5000]

Apple platform

iOS

Framework version

net9.0-*

Affected platform version

.net 9

Description

We just upgraded from a stable build environment with VS2022, to the new VS2026. We are leaving our main application targeting .net 9 for the time being. Part of the upgrade meant updating XCode to 26.5 on the paired Mac, so it has been a significant change of environment.

VS2026 successfully pairs to the Mac, and we can do F5 build-and-debug runs successfully as well as build and deploy Release builds for internal testing. No problems there.

Unfortunately, our CLI build script for production builds is now broken. It fails with the following error:

C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk.net9.0_26.5\26.5.9002\tools\msbuild\Xamarin.Shared.targets(2025,3): error Could not find Microsoft.iOS in /Users/redacted/Library/Caches/Xamarin/XMA/SDKs/dotnet/packs/Microsoft.iOS.Sdk.net9.0_26.5/26.5.9002/.

I have looked in that "packs" folder and there are "Microsoft.iOS.Sdk.net9.0_18.0" and "Microsoft.iOS.Sdk.net9.0_26.0" entries, but indeed not the 26.5 one it is looking for. I do not understand how it has ended up like this, and being someone who relies upon VS to get the environment set up correctly on the Mac, I do not know how to fix it.

The command we are using to build/publish is below.

dotnet publish -f:net9.0-ios -p:ArchiveOnBuild=true -p:ServerAddress=redacted -p:TcpPort=58181 -p:ServerUser="redacted" -p:_DotNetRootRemoteDirectory="/Users/redacted/Library/Caches/Xamarin/XMA/SDKs/dotnet/" -p:CodesignKey="redacted" -p:CodesignProvision="redacted" /p:DotNetRuntimePath="/usr/local/share/dotnet/dotnet" /p:ServerPassword="redacted"

I seem to recall this happened once before, but cannot remember how I fixed it. I think someone advised manually copying some files from one location on the Mac to another.

Needless to say, this has broken our ability to deploy our app, so we are stuck.

Steps to Reproduce

I cannot imagine how one would reproduce this.

Did you find any workaround?

No response

Build logs

No response

[rolfbjarne]

-p:_DotNetRootRemoteDirectory="/Users/redacted/Library/Caches/Xamarin/XMA/SDKs/dotnet/"

Can you try removing this argument?

If that doesn't work, try this instead:

-p:_DotNetRootRemoteDirectory="/Users/redacted/Library/Caches/maui/PairToMac/SDKs/dotnet/"

[divil5000]

Hi Rolf!

Removing the argument entirely results in the following:

C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk.net9.0_26.5\26.5.9002\tools\msbuild\Xamarin.Shared.targets(2025,3): error Could not find Microsoft.iOS in /usr/local/share/dotnet/packs/Microsoft.iOS.Sdk.net9.0_26.5/26.5.9002/.

Setting it to the alternate path you gave me seems to have worked. Thank you.

Why does this happen, please? Should the tools be being updated? Have I missed some kind of bulletin that should have alerted me to the need to change the command line? Documentation on how to build ios projects from the command line still advises the argument I originally had.

[divil5000]

Also, is it safe now to delete the /Users/redacted/Library/Caches/Xamarin/ directory if it's no longer used? There are 5gigs of files in there.

[rolfbjarne]

Why does this happen, please?

In VS 2026 we changed the directory where VS installs .NET on the Mac from ~/Library/Caches/Xamarin/XMA/SDKs/dotnet/ to ~/Library/Caches/maui/PairToMac/SDKs/dotnet/, so when you passed the old path, the build would still try to use the .NET version installed by VS 2022, not 2026.

Also, is it safe now to delete the /Users/redacted/Library/Caches/Xamarin/ directory if it's no longer used? There are 5gigs of files in there.

Yes, that's safe.

FWIW you can delete the new directory too if it gets big; it's a cache, so everything needed will just be re-installed the next time you connect to the Mac from VS.

Setting it to the alternate path you gave me seems to have worked. Thank you.

That's great! I'll close this then.

[divil5000]

Thank you.

It seems odd to close this issue without any acknowledgment that presumably lots of people are running into it, and that something needs to be fixed, even if it's just an update to the documentation that currently advises my former argument (link below).

https://learn.microsoft.com/en-us/dotnet/maui/ios/deployment/publish-cli?view=net-maui-10.0

[rolfbjarne]

It seems odd to close this issue without any acknowledgment that presumably lots of people are running into it, and that something needs to be fixed, even if it's just an update to the documentation that currently advises my former argument (link below).

https://learn.microsoft.com/en-us/dotnet/maui/ios/deployment/publish-cli?view=net-maui-10.0

Ah good idea, I've filed an issue to get the docs updated: dotnet/docs-maui#3488