[Question] Packaging Platform specific from Vendor dll

Details about Problem

NuGet product used => dotnet.exe:

I tried multiple version of dotnet:

• 3.1.201 (dotnet nuget 5.5.0.4)
• 5.0.100-preview.3.20216.6 (dotnet nuget 5.6.0.4)

VS version (if appropriate):
VS 16.6 Preview 5

OS version (i.e. win10 v1607 (14393.321)):
Microsoft Windows [Version 10.0.19619.1000]

Worked before? If so, with which NuGet version:
Can't tell

Detailed repro steps so we can see the same problem

1. Clone the repo https://github.com/tebeco/NativeLibNugetStuff/
2. read https://github.com/tebeco/NativeLibNugetStuff/blob/master/README.md
3. i'm trying to get dotnet build works on the SLN (as opposed to the build.ps1 that have to split the build process in 2 and complexify stuff)

I'm looking for a nice way to be able to have ProjectReference working when ManagedWrapper are already "built in"
I had to use PublishBuildOutput to false to tell the compiler to leave me alone in Corp.Common.ThirdPartPackaged as I got 0 sources (that may be a mistake on my side TBH)

With PackageReference :

With ProjectReference :

Sample Project

https://github.com/tebeco/NativeLibNugetStuff/
https://github.com/tebeco/NativeLibNugetStuff/blob/master/README.md

Workaround

The only workaround i see here would be to split in half the repo and the build to have a 2 step build process to be sure the nuget is produced
As it would fix the "side effect" by them self that would not fix the issue and would make the build more complexe

Start with the linked NativeLibNugetStuff README, then reproduce the reported dotnet build on the SLN and compare it with build.ps1. Review how ProjectReference, PackageReference, PublishBuildOutput, and the vendor DLL packaging are used; done means the supported behavior or remaining limitation is established and documented.