dotnet build not finding Xamarin

Question

When running dotnet build in my project, I have the following error:

/path/to/repo/Toolkit/My.Company.Toolkit.Platform.Android/My.Company.Toolkit.Platform.Android.csproj(91,3): error MSB4019: The imported project "/usr/local/share/dotnet/sdk/7.0.102/Xamarin/Android/Xamarin.Android.CSharp.targets" was not found. Confirm that the expression in the Import declaration "/usr/local/share/dotnet/sdk/7.0.102//Xamarin/Android/Xamarin.Android.CSharp.targets" is correct, and that the file exists on disk.
/path/to/repo/Toolkit/My.Company.Toolkit.Platform.iOS/My.Company.Toolkit.Platform.iOS.csproj(195,3): error MSB4019: The imported project "/usr/local/share/dotnet/sdk/7.0.102/Xamarin/iOS/Xamarin.iOS.CSharp.targets" was not found. Confirm that the expression in the Import declaration "/usr/local/share/dotnet/sdk/7.0.102//Xamarin/iOS/Xamarin.iOS.CSharp.targets" is correct, and that the file exists on disk.

I confirm that /usr/local/share/dotnet/sdk/7.0.102/Xamarin/iOS/Xamarin.iOS.CSharp.targets does not exist.
But I don't know how to install it there.

The reference to Xamarin is defined in the csproj like this <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />.

When I build from Visual Studio I have no issues. And if I try to re-install Xamarin, it says it is already installed.

I am on MacOS.

[UPDATE]

I uninstalled everything (Visual Studio, SDKs/Runtime, dotnet, etc). Installed just Visual Studio 2022 for Mac.

➜  ~ dotnet --info
.NET SDK:
 Version:   7.0.102
 Commit:    4bbdd14480

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  13.1
 OS Platform: Darwin
 RID:         osx.13-arm64
 Base Path:   /usr/local/share/dotnet/sdk/7.0.102/

Host:
  Version:      7.0.2
  Architecture: arm64
  Commit:       d037e070eb

.NET SDKs installed:
  6.0.405 [/usr/local/share/dotnet/sdk]
  7.0.102 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.13 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.2 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.13 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.2 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

Now if I try to build the project in the terminal I still have the same error. But if I try to build it from Visual Studio I have a different error.

I have this error in the build output

Target RazorGenerateComponentDeclaration:
    /usr/local/share/dotnet/dotnet exec "/Users/redacted/Library/Caches/VisualStudio/17.0/MSBuild/36265_3/Sdks/Microsoft.NET.Sdk.Razor/build/netstandard2.0/../../tools/netcoreapp3.0/rzc.dll" generate
    -s
    /Users/redacted/Developer/repositories/bcee/Toolkit/MyCompany.Toolkit.Platform.Web/_Imports.razor
    -r
    _Imports.razor
    -o
    /Users/redacted/Developer/repositories/bcee/Toolkit/MyCompany.Toolkit.Platform.Web/obj/Debug/netstandard2.1/RazorDeclaration/_Imports.razor.g.cs
    -k
    component
    -p
    /Users/redacted/Developer/repositories/bcee/Toolkit/MyCompany.Toolkit.Platform.Web
    -t
    obj/Debug/netstandard2.1/MyCompany.Toolkit.Platform.Web.RazorComponents.declaration.json
    -v
    3.0
    -c
    Default
    --root-namespace
    MyCompany.Toolkit.Web
    --csharp-language-version
    8.0
    --generate-declaration
    
    The application to execute does not exist: '/Users/redacted/Library/Caches/VisualStudio/17.0/MSBuild/36265_3/Sdks/Microsoft.NET.Sdk.Razor/build/netstandard2.0/../../tools/netcoreapp3.0/rzc.dll'
    /Users/redacted/Library/Caches/VisualStudio/17.0/MSBuild/36265_3/Sdks/Microsoft.NET.Sdk.Razor/build/netstandard2.0/Microsoft.NET.Sdk.Razor.Component.targets(106,5): error : rzc generate exited with code 129.
Done building target "RazorGenerateComponentDeclaration" in project "MyCompany.Toolkit.Platform.Web.csproj" -- FAILED.

Done building project "MyCompany.Toolkit.Platform.Web.csproj" -- FAILED.

Build FAILED.

The tools directory does not exists.

score 2 · Answer 1 · answered Jan 24 '23 at 17:46

2

The Xamarin tool chain was built upon Mono, so everything you triggered in VS for Mac is kindly processed by MSBuild for Mono (at Mac terminal you can use msbuild --version to learn more).

dotnet build, however, was designed exclusively for .NET Core based projects, so by default it won't be able to handle Xamarin projects, but only .NET MAUI.

As legacy Xamarin projects are going away soon, you should start to migrate to MAUI as soon as you can,

https://dotnet.microsoft.com/en-us/platform/support/policy/xamarin

answered Jan 24 '23 at 17:46

Lex Li

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Thank you for the clarification. Do you have an idea about the `rzc generate exited with code 129` issue I am getting in Visual Studio when trying to build the Blazor project? – grandouassou Jan 24 '23 at 20:35
@grandouassou please post a new question for that. – Lex Li Jan 24 '23 at 21:19
https://stackoverflow.com/questions/75231867 – grandouassou Jan 25 '23 at 09:23

score 1 · Accepted Answer · answered Jan 24 '23 at 07:15

At fisrt, you said:

When I build from Visual Studio I have no issues.

The cause should be when you build from the Visual Studio. The framework your project used is .netstandard 2.0. You can check the project.csproj file and the SDK in the /usr/local/share/dotnet/sdk.

In addition, you can check this case which has the similar error as yours. According to it, if the .net version is not compatible with the xamarin will also get this error. dotnet/sdk/7.0.102 should be the .net 7 which is compatible with the .net maui not the xamarin. So you can't use the dotnet build the project.

You can try to find the right value of the MSBuildExtensionsPath and set it in the android and ios .csproj file according to this case which is about set the project's MSBuildExtensionsPath.

Finally, you can try the solution in this case which has the same error message.

dotnet build not finding Xamarin

2 Answers2