dotnet build for .net 4.7 library fails citing missing references

Steps to reproduce

I have a ASP.Net Core 2 web application with class libraries that target the .net 4.7 framework. Visual Studio compiles fine but dotnet build fails. I’ve tracked the errors down to the class libraries which I’ve switched to use. I’ve followed the workarounds here (https://github.com/dotnet/standard/issues/481) and switched the library to use PackageReferences in the .csproj file and remove the packages.config. After some initial issues VS compiles fine and nuget restore works without issue but dotnet build still fails.

Expected behavior

dotnet build succeeds.

Actual behavior

Multiple errors about missing assemblies (ie Nuget Package references).

ApplicationSupport\EmailConfiguration.cs(4,7): error CS0246: The type or namespace name 'Newtonsoft' could not be found (are you missing a using directive or an assembly reference?) [C:\Dev\Neptune\Neptune.Common\Neptune.Common.csproj]

Environment data

dotnet --info output:

.NET Command Line Tools (2.1.2)

Product Information: Version: 2.1.2 Commit SHA-1 hash: 5695315371

Runtime Environment: OS Name: Windows OS Version: 10.0.16299 OS Platform: Windows RID: win10-x64 Base Path: C:\Program Files\dotnet\sdk\2.1.2\

Microsoft .NET Core Shared Framework Host

Version : 2.0.3 Build : a9190d4a75f4a982ae4b4fa8d1a24526566c69df

[krishnan-unni]

Not sure if anyone is still facing this issue without a solution. After some experiments I found out that the issue is with dotnet cli’s having trouble restoring the nuget packages and referencing them properly for the old style projects. I have 2 solutions for this:

1. You can convert the old style csproj file to the new SDK style project file and build.
2. In case you can’t or don’t want to change the csproj file to the new style (due to its complexity of change or other reasons) you can change the nuget settings to use package.config (with project.json file) format instead of PackageReference format and then build. Dotnet cli would build fine.

[bradleypatton]

My suggestion or hope would be if dotnet could issue warnings rather than fail to build if it encounters framework assemblies (even if there are runtime errors later). The reason this is a big issue is that Visual Studio seems to support mixing full framework and .core packages. But then some functionality in VS breaks because under the covers it is calling dotnet and the cmdline is failing.

I’m in the process of trying to convert all of my code to .net core projects because I just don’t see the mixed code working very well.