I've changed the PackageReferences in my projects from Microsoft.AspNetCore.All to Microsoft.AspNetCore.App (without version number) as was suggested by the ASP.NET Core 2.0 to 2.1 migration guide. After that I got a bunch of build warnings like this:

_Warning NU1604: Project dependency Microsoft.AspNetCore.App does not contain an inclusive lower bound. Include a lower bound in the dependency version to ensure consistent restore results._

_Warning NU1602: [Project Name] does not provide an inclusive lower bound for dependency Microsoft.AspNetCore.App. An approximate best match of Microsoft.AspNetCore.App 2.1.0 was resolved._

The Microsoft.AspNetCore.App description here contains the following phrase: "The Microsoft.AspNetCore.App metapackage is not a traditional package that is updated from NuGet." If it's not a normal NuGet package, I would expect that I should not be getting NuGet warnings for it. Getting build warnings when everything is actually fine is annoying and creates a risk that after some time I'll stop paying attention to build warnings at all and miss some "genuine" warning.

I don't think NU1602 and NU1604 should be suppressed at the project level, as these warnings make sense for "normal" NuGet packages. I tried to disable these warnings for the PackageReferences for Microsoft.AspNetCore.App using the instructions from here:

<PackageReference Include="Microsoft.AspNetCore.App">
  <NoWarn>NU1602,NU1604</NoWarn>
</PackageReference>

I got fewer build warnings, but some projects still reported them. These projects themselves did not contain PackageReferences for Microsoft.AspNetCore.App, but they referenced other projects that did. To suppress warnings for these projects, I had to add PackageReferences for Microsoft.AspNetCore.App to their .csproj files. Then I was able to build the solution without warnings.

If it's relevant - I'm using Visual Studio 2017 Community Edition, version 15.7.3

My question is - is there a simpler way to suppress build warnings for Microsoft.AspNetCore.App package? It would be also good to update documentation for this metapackage and include an instruction of how to suppress them.

OleksandrKrutykh on 5 Jun 2018

👍9

@JunTaoLuo please comment.

Rick-Anderson on 6 Jun 2018

The warnings you are getting suggests that you are using the 2.0 SDK which doesn't contain the logic that sets the implicit versions for Microsoft.AspNetCore.App. Do you have the latest 2.1 SDK (2.1.300) installed? See: https://www.microsoft.com/net/download/

JunTaoLuo on 6 Jun 2018

Hello @JunTaoLuo,

I have it installed on my workstation:

screenshot

I also have a lot of older SDKs installed, so that might be causing the problem...

OleksandrKrutykh on 6 Jun 2018

Hmm then I'm curious why it's not working. What does dotnet --info say? I'm not sure installing previous SDKs will resolve the issue but it may help.

JunTaoLuo on 6 Jun 2018

Here's the output of dotnet --info:

.NET Core SDK (reflecting any global.json):
 Version:   2.1.300
 Commit:    adab45bf0c

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.17134
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\2.1.300\

Host (useful for support):
  Version: 2.1.0
  Commit:  caa7b7e2ba

.NET Core SDKs installed:
  1.0.0-preview2-003131 [C:\Program Files\dotnet\sdk]
  1.0.0-preview2-1-003177 [C:\Program Files\dotnet\sdk]
  1.0.0 [C:\Program Files\dotnet\sdk]
  1.0.2 [C:\Program Files\dotnet\sdk]
  1.0.3 [C:\Program Files\dotnet\sdk]
  1.0.4 [C:\Program Files\dotnet\sdk]
  1.1.0 [C:\Program Files\dotnet\sdk]
  2.0.0 [C:\Program Files\dotnet\sdk]
  2.0.2 [C:\Program Files\dotnet\sdk]
  2.0.3 [C:\Program Files\dotnet\sdk]
  2.1.2 [C:\Program Files\dotnet\sdk]
  2.1.4 [C:\Program Files\dotnet\sdk]
  2.1.100 [C:\Program Files\dotnet\sdk]
  2.1.101 [C:\Program Files\dotnet\sdk]
  2.1.102 [C:\Program Files\dotnet\sdk]
  2.1.103 [C:\Program Files\dotnet\sdk]
  2.1.104 [C:\Program Files\dotnet\sdk]
  2.1.200 [C:\Program Files\dotnet\sdk]
  2.1.201 [C:\Program Files\dotnet\sdk]
  2.1.300 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 1.0.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.1.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.1.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.1.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

OleksandrKrutykh on 6 Jun 2018

Hmm I'm unable to reproduce the issue locally, but I also don't have many older SDKs installed so that may be the problem. Are you able to reproduce the issue on the command line with dotnet restore? If so, can you collect the msbuild binlog and share it with me so I can debug (run dotnet restore /bl and attach the msbuild.binlog)?

JunTaoLuo on 6 Jun 2018

@JunTaoLuo, thank you for taking the time to look into that.

Yes, I'm getting the same warnings when running dotnet restore through command line
Here's the msbuild binlog for one of the projects: msbuild.zip. For your information - not all projects in my solution that reference Microsoft.AspNetCore.App produce NuGet warnings.

OleksandrKrutykh on 6 Jun 2018

For me following change in csproj project file helped: <Project Sdk="Microsoft.NET.Sdk"> -> <Project Sdk="Microsoft.NET.Sdk.Web">

My case was a class library project that was converted from 2.0 to 2.1 and had a following reference:
<PackageReference Include="Microsoft.AspNetCore.App" />

Using Visual Studio 15.7.3 and 2.1.300 SDK.

ToTameALand on 8 Jun 2018

Sorry for the slow response, but as @ToTameALand mentioned the problem here is that the SDK must be set to Microsoft.NET.Sdk.Web for the implicit version to be set correctly. The sample at https://docs.microsoft.com/en-us/aspnet/core/fundamentals/metapackage-app?view=aspnetcore-2.1 shows this but maybe we can make this more explicit @Rick-Anderson ?

JunTaoLuo on 8 Jun 2018

👍2

@JunTaoLuo, @ToTameALand, thank you for looking into this! You are right, all projects in my solution that produced the NuGet build warnings indeed use Microsoft.NET.Sdk instead of Microsoft.NET.Sdk.Web. I assume that they use Microsoft.NET.Sdk because they are class libraries, not ASP.NET Core projects. It looks like I should not have added references to Microsoft.AspNetCore.App there in the first place...

I've removed the references to Microsoft.AspNetCore.App from my class libraries, actual ASP.NET Core projects still reference Microsoft.AspNetCore.App. I don't get any warnings when building my solution now.

As regards https://docs.microsoft.com/en-us/aspnet/core/fundamentals/metapackage-app?view=aspnetcore-2.1, a warning like "Do not add a reference to Microsoft.AspNetCore.App to your class library, it won't work properly" could be included there, so that another developer wouldn't make the same mistake that I did.

OleksandrKrutykh on 9 Jun 2018

Same issue here, the comment https://github.com/aspnet/Docs/issues/6430#issuecomment-394864697
help me remove warning

ngohungphuc on 17 Jun 2018

When I install current SDK (2.1.301) and publish default web applicatation to azure with implicit version, I get:

HTTP Error 502.5 - Process Failure

App Service Development Console in Azure Portal:

> dotnet --info
D:\home\site\wwwroot
.NET Core SDK (reflecting any global.json):
 Version:   2.1.300
 Commit:    32f29b6eb9

> dotnet webapplication1.dll
D:\home\site\wwwroot
It was not possible to find any compatible framework version
The specified framework 'Microsoft.AspNetCore.App', version '2.1.1' was not found.

If it is recommended to use implicit version, then WTF?

Liero on 22 Jun 2018

👍2

It looks like azure doesn't have the 2.1.301 SDK or the 2.1.1 runtime installed yet. @davidebbo do you know when the new bits will be available?

JunTaoLuo on 25 Jun 2018

Previous comment was 3 days ago, and deployment completed Friday morning PST. My guess is that at the time @Liero tried it wasn't there yet, but got there shortly after. Please try again.

davidebbo on 25 Jun 2018

@JunTaoLuo: my point is, that following recommended practices results in very poor developer experience. Do you think that application startup failure caused just by installing latest SDK locally that differs only in patch version is predictable and expected behavior? If no, then do something about it.

Liero on 26 Jun 2018

@Liero In general we don't expect to increment the implicit version of the Microsoft.AspNetCore.App metapackage during patches, as described in the documentation: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/metapackage-app?view=aspnetcore-2.1. However, during this release, we realized there were some issues with our version ranges that could lead to more warnings and errors in future patches so we needed to modify the metapackage and increment the implicit version used by apps targeting netcoreapp2.1. We hope we don't have to do this in the future so this should not happen again.

JunTaoLuo on 26 Jun 2018

A key issue here is that if we compile with warnings as errors (as we do) this will break the build, unless we explicitly add NoWarn for these errors. I think it is problematic to force a NoWarn whenever this dependency is referenced for customers that want to treat warnings as errors.

iancooper on 27 Jun 2018

@iancooper what kind of warnings are you seeing? The reason we updated the base implicit version this release was to avoid such warnings so I'd be interested to see why it didn't work for you.

JunTaoLuo on 27 Jun 2018

I am using Razor pages and seeing this warning. How do I fix the issue? Here is my .csproj file:

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

  <PropertyGroup>
    <TargetFramework>netcoreapp2.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.App">
        <NoWarn>NU1604</NoWarn>
    </PackageReference> 
  </ItemGroup>

</Project>

mrlife on 28 Jun 2018

@mrlife <Project Sdk="Microsoft.NET.Sdk.Web">

Rick-Anderson on 28 Jun 2018

👍1

The implicit version gave me build errors in VSTS, although I am using SDK 2.1.301 there (as I do locally). I reference the Microsoft.Net.Sdk.Web and updated the other necessary NuGets for my project to 2.1.1 but in VSTS the build fails with NU1107 (version conflict), see https://github.com/aspnet/Home/issues/3250

zuckerthoben on 5 Jul 2018

After reviewing customer feedback and lots of design discussion, we think the implicit package version has created more confusion than help. We are planning to change course and go back to recommending using the Version attribute on the PackageReference to Microsoft.AspNetCore.App/All.

See https://github.com/aspnet/Home/issues/3292.

natemcmaster on 8 Jul 2018

👍5 😕2 😄1

I am struggling with this right now with a ton of these errors:

If I pin my App version at 2.1.4 I have no issues. I do not understand these errors, my test project never references Microsoft.AspNetCore.Authentication 2.0.3.0 my parent project never references Microsoft.AspNetCore.Authentication 2.1.1.0. And Icant even find any transitive dependencies that reference those numbers. So what is going on here? Did we decide that everyone should start pinning versions? I may have misread but the linked aspnet issue says "[Nate: July 9]: this was not implemented, and we are not planning to implement right now." so are we NOT deciding to stop generating templates using an implicit .App version?

Test Project

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

  <PropertyGroup>
    <TargetFramework>netcoreapp2.1</TargetFramework>
    <RootNamespace>MyIdentityServer.UnitTests</RootNamespace>
    <LangVersion>latest</LangVersion>
    <IsPackable>false</IsPackable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />
    <PackageReference Include="Moq" Version="4.9.0" />
    <PackageReference Include="xunit" Version="2.4.0" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\..\src\MyIdentityServer\MyIdentityServer.csproj" />
  </ItemGroup>

</Project>