netcoreapp2.0 is not compatible with netstandard2.0 ?

[srayuws]

Hi ,
I have 3 trivial projects here:

• CommonLib.csproj with target netstandard2.0
• OldImplement.csproj with target v4.7
• NewImplement.csproj with target newcoreapp2.0

Here is the problem:

It works fine if I reference the OldImplement in the CommonLib, everything works find.

But when i try to change the referenced project from the OldImplement to the NewImplement, I cannot build the CommonLib. And here is the error I got when I run dotnet build for CommonLib:

error NU1201: Project NewImplement is not compatible with netstandard2.0 (.NETStandard,Version=v2.0). Project NewImplement supports: netcoreapp2.0 (.NETCoreApp,Version=v2.0)

I have .Net CLI 2.0.2 installed.

My questions is: is this error by design, or it is possible to reference a netcoreapp project in a netstandard library?

[odytrice]

Why was this closed? I have the same problem on a build server. Could it be that the right SDK is not installed?

[odytrice]

Turns out I was making a netstandard2.0 project depend on netcoreapp2.0 application

[srayuws]

Hi @odytrice . The answer I got is: For new libraries, they should be implemented as netstandard. netcores and netfx could both reference netstandard projects, but not reverse. And everyone could reference netfx projects is for historical compatibility.