System.Threading.Tasks.Extensions package needs _._ placeholders for Xamarin platforms

[akoeplinger]

We're adding a facade for System.Threading.Tasks.Extensions.dll inbox so we'd like to add the placeholders for the usual Xamarin platforms to the package.

/cc @weshaggard

[weshaggard]

@akoeplinger we are in escrow mode for .NET Core 2.1 when do you guys need this?

[akoeplinger]

I don't think we're in a rush to get this. We found out about it because Roslyn is adding a dependency on this package.

/cc @marek-safar

[marek-safar]

@weshaggard 2.2 milestone seems to be too far away (months right?). Could we get it fixed sooner as customers seem to start hitting this?

[weshaggard]

@tarekgh it looks like you own this package is it this something you can do and drive?

[tarekgh]

@weshaggard could you please advise how we can do that? I am not familiar with that but I can follow up if I have some guidance.

[tarekgh]

I talked offline to @joperezr and he described how I can do that. I'll try to submit a PR for that.

[weshaggard]

It will be a PR similar to dotnet/corefx@6813af0#diff-f464c49eb9b66f6721df0d4e8ad4c14f

[tarekgh]

https://github.com/dotnet/corefx/issues/29828

[joperezr]

re-opening to track port to release branch.

[joperezr]

@weshaggard looks like @marek-safar needs this to ship before 2.2, any chance we would consider this for 2.1 or 2.1 servicing?

[danmoseley]

It sounded like there were other packages with this issue - system.Buffers? If so I'd like to bring them all together.

[joperezr]

Sorry, I didn't see that we have another issue that is already tracking the port of this on 2.1 along with other libraries (like SYstem.Buffers) so I'll close this one as a dupe to dotnet/corefx#29828

[marek-safar]

These were filled as separate issues because they are addressing separate problems. Hence this is not dupe of dotnet/corefx#29828 because the fixes need to land at different time with the current way of shipping the core nugets.

This one should have 2.1.x milestone

[weshaggard]

Reopening to track this particular issue for 2.1 servicing.

[tarekgh]

Fixed by dotnet/corefx#29922 in release/2.1 branch. Will ship in 2.1.1 release