Support for dotnet 6.0

[ethangk]

Description

Given the recent release of dotnet 6.0, I've attempted to bump my project to that version. We're running into issues with FSharpLint not supporting dotnet 6.0, from what we can see.

Repro steps

Bump the dotnet version in the docker container to dotnet 6.0. dotnet tool restore works ok, but running:
dotnet fsharplint lint projectName.fsproj results in

It was not possible to find any compatible framework version
The framework 'Microsoft.NETCore.App', version '5.0.0' (x64) was not found.
  - The following frameworks were found:
      6.0.0 at [/usr/share/dotnet/shared/Microsoft.NETCore.App]

You can resolve the problem by installing the specified framework and/or SDK.

The specified framework can be found at:
  - https://aka.ms/dotnet-core-applaunch?framework=Microsoft.NETCore.App&framework_version=5.0.0&arch=x64&rid=debian.11-x64

This is using the most recent (0.20.2) version of FSharpLint.

Thanks!

[knocte]

Hello, thanks for submitting this bug report!

I have the feeling that this would be fixed by adding "rollForward": "major" to our global.json file.

Do you mind testing this fix, and if it works, submit a PR? Thanks

[ethangk]

Thanks for getting back to me so quickly. I've cloned the project locally and added the flag to the global.json then built. I'm trying to reference it from my project (by adding the local path as an additional source), so that I can test and it's still not working. I suspect it's using the nuget version instead of this local version. I'm fairly new to the dotnet package world. What's the easiest way to verify this/ force it to use the local version?

[knocte]

I think you need to generate a nupkg file and use it locally, but don't remember from the top of my head how to do it (especially taking in account that Paket is being used).

[jp-fournier-dev]

My team has the same issue as @ethangk
I've taken to trying the proposed fix, by building it locally and copying the output folder too a container that runs only net6, without any success.

After doing some research I fell on this thread : dotnet/sdk#16427

Setting this excerpt in the project file for the tool made it run on a 6.x runtime

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

From what I observed, doing the change in the config.json file only changed the behaviour at build time, where if I ; rollForward: latestMajor it will build using 6.x for 5.x, but when trying to launch the tool, it fails with the original error.

I can create a PR with the unique change if you think this is a valid fix. Otherwise we can also upgrade to 6.x / multitarget. What's your view on this ?

[knocte]

without any success.

Thanks for testing this!

From what I observed, doing the change in the config.json file

I'm guessing you mean global.json, not config.json.

I can create a PR with the unique change

Yes please!

if you think this is a valid fix

Looks like valid, but if you said you tested it and it works, it must be valid!

Otherwise we can also upgrade to 6.x / multitarget. What's your view on this ?

TBH I think multi-targetting is a bit messy, I think it's better to avoid it if we can. Ideally we should only support .NETStandard 2.0 (which works for both legacy framework 4.x and .NETCore/.NET5/.NET6), however we're not a library, but a tool :)

[jp-fournier-dev]

I'm guessing you mean global.json, not config.json.

Yes indeed !

Does sound good to me! I'll take care of the PR on monday

[ethangk]

Great, thanks for looking at this. I'd planned on taking a look today