Remove unnecessary placeholders in .nuspec's

[wtgodbe]

In release/3.0, we needed placeholder files for NetStandard1.3 and NetCoreApp2.1 in these 2 nuspecs, but that's not the case in release/3.1 or master. Their existence caused nuget package validation to fail.

@dougbu @Pilchie do you think it's worth taking this for 3.1-preview1? I lean towards waiting for preview2, since it doesn't block the build, and the effect on customers is minimal (an extra empty file in these 2 nupkg's).

[Pilchie]

Can you explain what changed such that we don't need it anymore?

[wtgodbe]

These 2 packages contain executables & don't place anything in their lib folders, which nuget expects them to do. In 3.1/master, the package has the same TargetFramework as the rest of the repo, and handles placing the placeholder file in a different way: https://github.com/aspnet/EntityFrameworkCore/blob/release/3.1/src/dotnet-ef/dotnet-ef.nuspec#L15

It looks like what happened was we handled this nuget error differently in the 2 branches, and since 3.0 merges up to 3.1/master, and 3.0 has hardcoded netcoreapp2.1 / netstandard1.3 TFMs for these 2 packages (which don't match 3.1/master), we wound up with a redundant workaround for TFMs that didn't need to exist in the packages.

We could just change the TFMs in 3.0 to match 3.1/master, and use the same workaround in all 3 branches. Or given that we're already in a weird-ish state, we could take this PR, then resolve the auto-merge PR in favor of 3.1.

[dougbu]

It's hard to tell in GitHub. Are you deleting the _._ files?

[wtgodbe]

Yes

[Pilchie]

Definitely want to hear from the EF team here.

[smitpatel]

The code being deleted was added by build team only during release/3.0 and now it is being removed.
Questions:

• Why did EFCore.Analyzers needed placeholder for ns1.3 in 3.0 but does not need for ns2.0 in 3.1. (Brice updated TFM for that). Also EFCore.Analayzer targets different tfm than rest of the repo.
• dotnet-ef - csproj targeted netcoreapp3.0 and moved to 3.1 now. (intentional? @bricelam). The nuspec defined tfm to be netcoreapp2.1 & related placeholder in 3.0. Now it does not have that code and uses netcoreapp3.1 tfm. What was the reason that we used tfm (for some purpose) as netcoreapp2.1 in 3.0 release but we are using netcoreapp3.1 now.
• Did anything change in build infra which required placeholder for tfms in past and now it does not.

[wtgodbe]

I believe we started needing these placholders due to a recent Nuget update. I don't know why we decided to change the TFMs in 3.1, but that's what led to the disparity between the 2 workarounds.

Why did EFCore.Analyzers needed placeholder for ns1.3 in 3.0 but does not need for ns2.0 in 3.1. (Brice updated TFM for that).

The following as added in 3.1, which handled the placeholder for Netstandard2.0. The NetStandard1.3 placeholder became redundant at that point.
https://github.com/aspnet/EntityFrameworkCore/pull/18214/files#diff-45710a11efabd62dcc38b8679bdea05cR12

[Pilchie]

I'm going to guess that changing the TFM in 3.1 wasn't the right thing to do :-/

[dougbu]

I'm going to guess that changing the TFM in 3.1 wasn't the right thing to do :-/

I seem to remember a conversation in one of the GitHub PRs where the resolution for the tool was to move forward. Of course, that may have been the wrong call and we should definitely do the Right Thing:tm: going forward. (@ajcvickers may have been out when we had that conversation.)

So, @aspnet/efteam does the latest and greatest dotnet ef command need to be runnable against older projects e.g. netcoreapp2.1 ones?

[bricelam]

Does the latest dotnet ef command need to be runnable against older projects e.g. netcoreapp2.1 ones?

Yes. But that doesn't have anything to do with the target framework of dotnet-ef. We should target the same same framework as the tools that ship as part of the SDK. It's reasonable to say that you need the 3.1 SDK to use dotnet-ef 3.1.

The target frameworks of the ef project determine which target frameworks a project can use. (Should be net461+netcoreapp2.0)

[leecow]

tactics approved

[wtgodbe]

@bricelam is there work necessary in the dotnet-ef project in 3.1? If so, should it be done in this PR, or separately in another PR for 3.1-preview2?

[bricelam]

Seems fine. Filed #18316 to double-check that everything is working as expected.

[wtgodbe]

Merging since release/3.1 is already the preview2 branch