Why is my Xamarin.iOS app being compiled with C# 8 even though the project specifies version 9?

[salgiza]

Type: Question

Enter Task Name: XamariniOS

Environment

• Server - Azure Pipelines
• Agent - Hosted

Issue Description

I have a Xamarin app/sln where all the csproj files have lang version 9 specified in them, in all of their built configurations:

<LangVersion>9.0</LangVersion>

and I've defined 'macOS-latest' as the vmImage. The thing is that, no matter what I do, I always get this kind of errors when the app is being compiled in the XamariniOS task:

Feature 'xxxx' is not available in C# 8.0. Please use language version 9.0 or greater.

I mean, I don't even get an error message saying that c# 9 is not supported or anything, the agent just seems to be ignoring the lang version defined in the project and trying to compile it using c# 8 :(

I even tried to compile the app using bash instead of the XamariniOS task (as mentioned here: #14171 ), but I got the same result.

And, of course, the task that compiles the android version of the app, using the same vmImage, does it without any problems (and compiling the iOS version locally works fine as well).

I would really appreciate it if anyone could point me to what could be causing the XamariniOS task to ignore the LangVersion specified in the csproj files (I'm sure it must be something silly, but I'm totally stuck).

[anatolybolshakov]

Hi @salgiza sorry for the delay - could you please share your pipeline logs in debug mode? You can send them to my email - [email protected]

[salgiza]

Hi @anatolybolshakov, I just sent the logs to your email (just wanted to confirm that I was the author of the email! 🙂 ).

[anatolybolshakov]

Per logs investigation - seems that this warning comes from msbuild itself, and task generates command properly for this tool - I would suggest to open a ticket in msbuild repo to get right eyes on it.
I'm closing this one as external at the moment - @salgiza please let us know if you have any other questions.