Possible MissingMethodException caused by System.ValueTuple

[alsami]

As discussed here using System.ValueTuple requires the package System.ValueTuple to be referenced when targeting net461

As @alistairjevans stated in the discussion linked above, we are already using it and not getting any compiler errors (which should not be the case for net461).

Here also an issue on the roslyn repository that states, that this missing include was added with net471.

Easiest and safest fix would be to have a conditional package-reference

<PackageReference Condition="$(TargetFramework) == 'net461'" Include="System.ValueTuple" Version="4.5.0"  />

That does not explain why there is no compiler error though.

[alistairjevans]

Are you able to recreate this locally @alsami, and get a MissingMethodException?

[alsami]

Are you able to recreate this locally @alsami, and get a MissingMethodException?

@alistairjevans will get a sample repo ready later today.

[alsami]

So I just looked into it a bit and interestingly there is no way to make it throw an error. I double checked if that problem in general does exist and created a small repository that already fails to compile without the uncommented package-reference in the csproj file.

I then thought it must be somewhat included through some dependency that we have on net461 but didn't find it for Microsoft.Bcl.AsyncInterfaces or for System.ComponentModel.Composition.

[alistairjevans]

Perhaps it's the netstandard2.0 reference?

Or something to do with this comment in the issue you linked?

[alsami]

Perhaps it's the netstandard2.0 reference?

Or something to do with this comment in the issue you linked?

I figured it out now. If you uncomment the reference to Microsoft.Bcl.AsyncInterfaces in the Autofac project, it fails to compile on net461 in the sample that uses value-tuples.

Not sure why though, I can't find it as a dependency of the package, not even in the peer dependency of that said package. Closing this, sorry for the confusion! :)

[alistairjevans]

No probs, good to get to the bottom of stuff like this.