[Feature Request] Global tool .NET 7 support

[Apollo3zehn]

Is your feature request related to a problem? Please describe.
I have only .NET 7 installed on my system (Kubuntu 22.10) by just downloading the SDK. I have also a .NET 6 SDK in a different folder but to make the global tool work I need to do the following:

sudo rm /usr/bin/dotnet
sudo ln -s /home/<user>/Dokumente/Software/dotnet-6.0/dotnet /usr/bin/dotnet
DOTNET_ROOT=/home/<user>/Dokumente/Software/dotnet-6.0 /home/<user>/.dotnet/tools/docfx metadata

And then switch back when done.

Describe the solution you'd like
I would be great if the tool is also compiled for .NET 7 so this is not required anymore.

Additional context
https://github.com/dotnet/docfx/releases/tag/v2.60.0-preview.2

[KalleOlaviNiemitalo]

dotnet/sdk#26417 (comment) seems to recommend that .NET tool packages allow major version roll-forward.

[KalleOlaviNiemitalo]

  <PropertyGroup>
    <RollForward>Major</RollForward>
  </PropertyGroup>

See dotnet/sdk#3296, https://learn.microsoft.com/dotnet/core/project-sdk/msbuild-props#rollforward.

@Apollo3zehn you may be able to override by setting DOTNET_ROLL_FORWARD=Major in the environment.

[Apollo3zehn]

Thanks @KalleOlaviNiemitalo! While this in principal works (the build output is generated successfully), it gives me the following warning multiple times:

[KalleOlaviNiemitalo]

Huh so the problem is not only running the DocFX tool within .NET SDK 7, but also running .NET SDK 7 (with MSBuild and NuGet) during docfx metadata.

[KalleOlaviNiemitalo]

Why are the NuGet DLLs even included in the DocFX tool package? Searching for "NuGet." in the other DLLs of the tool package does not find any hits, except in Newtonsoft.Json.dll, which contains the text https://www.nuget.org/packages/Newtonsoft.Json.Bson.

[Apollo3zehn]

Since it happens in a AssemblyLoadContext method I guess that a plugin is being loaded and that this plugin has the Nuget dependency.

[KalleOlaviNiemitalo]

DocFX uses MSBuildLocator to find the MSBuild assemblies so that they need not be included in the DocFX package. I hope the NuGet assemblies could be likewise loaded from the Visual Studio or .NET SDK installation rather than shipped with DocFX.

[paulushub]

Since it happens in a AssemblyLoadContext method I guess that a plugin is being loaded and that this plugin
has the Nuget dependency.

I found no instance of the AssemblyLoadContext class or the System.Runtime.Loader namespace. Which code are you referring to here?
The assembly referencing NuGet.ProjectModel and NuGet.Packaging.Core compiles successfully after removing them.

[paulushub]

I would be great if the tool is also compiled for .NET 7 so this is not required anymore.

How about using a Docker?

[Apollo3zehn]

I am referencing to the stack trace in my screenshot above. I'll make a minimum sample on Monday to see if the error is related to my project targeting multiple frameworks (including .NET 6).

Docker would surely work but I think its a bit overkill and I would first like to understand what's going wrong here.

[paulushub]

@Apollo3zehn DocFX for .NET 6.x is just trying to make way for a first release, so .NET 7.x will only add more work now.

Here is a thread on managing multiple .NET Core on Linux, if that will be useful:
https://stackoverflow.com/questions/39233865/how-to-install-multiple-versions-of-net-core-side-by-side-on-ubuntu

Many preferred Farvashani's answer, which is detailed here
https://devdojo.com/farvashani/how-to-install-multiple-versions-of-net-core-side-by-side-on-linux

[Apollo3zehn]

@paulushub Thank you, it worked.