Unresolved symbols in FCS solution

[auduchinok]

This line now produces an error (despite the project actually building fine):

fsharp/src/fsharp/absil/illib.fs

Line 1157 in 4ee2816

member x.Values = contents.Values |> List.concat

It probably happens due to a recent Map change in FSharp.Core. I thought we were trying to be able to use the released FSharp.Core package in FCS, so this error is unexpected. It's also interesting why the project builds (i.e. what FSharp.Core it actually uses?) and why the tooling behaves differently?

Rider:

Visual Studio 2019:

[vzarytovskii]

May be related to: #11968 and #12108
@KevinRansom fyi

[auduchinok]

@dsyme @KevinRansom What FSharp.Core version these changes are going to land to? Will it be 5.0.3 or 6.0?
When FSharp.Core 5.0.3 is going to be released?

Right now working on FCS is much harder due to these errors. Also, we'd prefer to keep using stable FSharp.Core versions and update when needed (there's some additional work we have to do update the bundled FSharp.Core).

[dsyme]

It looks like

  <ItemGroup Condition="'$(FSHARPCORE_USE_PACKAGE)' == 'true'">
    <PackageReference Include="FSharp.Core" Version="$(FSharpCorePreviewPackageVersion)" />
  </ItemGroup>

should be

  <ItemGroup Condition="'$(FSHARPCORE_USE_PACKAGE)' == 'true'">
    <PackageReference Include="FSharp.Core" Version="$(FSharpCoreShippedPackageVersionProperty)" />
  </ItemGroup>

[dsyme]

I mean, if we're using a package it should be a shipped package.

[auduchinok]

@dsyme Could you reopen it?

[vzarytovskii]

It seems that #12149 didn't fix it, going to reopen it.

[dsyme]

@auduchinok Could you give me steps to repro this?

1. msbuild service/FSharp.Compiler.Service.sln works fine
2. I open service/FSharp.Compiler.Service.sln in VS2022 preview and the errors aren't appearing.

There is however a warning marker on this 5.0.2 FSharp.Core references which I don't understand (and can't work out what warning that is referring to)

[auduchinok]

I open service/FSharp.Compiler.Service.sln in VS2022 preview and the errors aren't appearing.

They do appear for me in VS2019 and Rider 2021.3 preview. I've reproduced it roughly like this:

cd fsharp
git clean -dfx
./build.cmd

and then open the FCS solution in an IDE.

What I've managed to discover is the conditional FSharp.Core reference is being ignored completely here, and another one transitively comes from FSharp.DependencyManager.Nuget project, where it's not conditional and always references the project output. I suspect the warning you see could be related here. The workaround that helps me is changing the reference in that project.

[dsyme]

What I've managed to discover is the conditional FSharp.Core reference is being ignored completely here, and another one transitively comes from FSharp.DependencyManager.Nuget project, where it's not conditional and always references the project output.

I see, yes, that makes sense, we should adjust that too