Suppressing warnings through project properties UI adds tfm condition in csproj file for multi targeting project

[mishra14]

Repro steps:

1. Create a new NetCore 2.0 Console App
2. Multi-target to netcoreapp2.0;net461:
   <TargetFrameworks>netcoreapp2.0;net461</TargetFrameworks>
3. Add a NuGet reference to a net 461 compat package like RestSharp
4. Build -> Show 2 warnings which seems to be another bug: Duplicate NU1701 warnings when multi-targetting to netcoreapp2.0 and net461 sdk#1474
5. Suppress warning NU1701 from Project->Properties->Build->Suppress Warnings
6. Edit the csproj file -

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFrameworks>netcoreapp2.0;net461</TargetFrameworks>
  </PropertyGroup>

  <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|netcoreapp2.0|AnyCPU'">
    <NoWarn>1701;1702;1705;NU1701</NoWarn>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="RestSharp" Version="105.2.3" />
  </ItemGroup>

</Project>

The issue here is that the user did not select netcoreapp2.0 while suppressing the warning but the csproj has netcoreapp2.0 in the condition.

Other Info:

if you try the same steps in a project that does not multi-target then the condition is fine -

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  </PropertyGroup>

  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
    <NoWarn>1701;1702;1705;NU1701</NoWarn>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="RestSharp" Version="105.2.3" />
  </ItemGroup>

</Project>

VS Version: 15.4.0 Preview 2 | d15rel/16828.0

cc: @natidea @emgarten

[davkean]

We need to design how this is going to work - whether we add a TFM switcher these pages, or we just make sure we don't persist it when we write the condition out.

[anangaur]

IMO, the ideal solution would be the first one that means implementing the TFM switcher with the default to all/any TFM. This should be followed by any NuGet work required.
@emgarten, @mishra14 is there any follow up work required on NuGet side with approach?

I also see this is marked for 15.6. Can this be considered for 15.5? I am okay with either approach - whichever is faster.

[davkean]

We're not going to be able to fit this in for 15.5. Does NuGet respect suppressing warnings per TFM?

[anangaur]

I am not positive. @mishra14 can confirm. If not, how difficult is it to remove TFM filter for NuGet warning suppression (2nd option)? For 15.5?

[davkean]

It needs investigation - we don't own that code. It lives in CPS and we'll need to add an extension point to override the behavior,

[mishra14]

NuGet currently considers the project wide warning properties to be framework independent. This can be changed if needed. But we need to consider if having no warn or warn as error per framework, make sense from a user point of view.

It would be great to have the framework condition removed as the first step!

[anangaur]

@davkean, Is this on track for 15.6?

[davkean]

No, given current priorities this is not on track for 15.6. @Pilchie When are we moving bugs to the "holding" pen that Matt was talking about?

[Pilchie]

Hopefully next week I'll get our 15.6 bugs sorted out.

[Pilchie]

sigh A bit longer than a week...

[kant2002]

Any idea then some progress could happens ?

[clairernovotny]

Bump? This is blocking the ability to suppress warnings per specific TFM in multi-targeting projects.