Content from NuGet copy to output issue

How to execute

As a prerequisites, you need .NET 7 to be installed (you can also downgrade the version needed by editing the 4 projects yourself).

You can build and run the test by running the script Check.ps1.

If you want to do more tests, you will need to update the $packVersions variable from that Check.ps1 script, as the cache will probably restore previous versions of the packages.

What to expect

Let's say that - for some reasons - my PackageA absolutely needs the file test.txt to be present in the final application binary folder to run correctly.

In PackageA.csproj, the file is declared as Content with the metadata PackageCopyToOutput set to true.

As expected, the project ProjectConsumingA consuming the generated PackageA package, will copy test.txt to its output.

When running the script Check.ps1, you can see these lines in the output, after build:

=============================================
test.txt has been successfully copied to ProjectConsumingA/bin/Debug/net7.0.
PackageA can run as expected.
=============================================

and after publish:

=============================================
test.txt has been successfully copied to ProjectConsumingA/bin/Debug/net7.0/publish.
PackageA can run as expected.
=============================================

So far, so good.

However, when the PackageA is referenced by a PackageB, and a ProjectConsumingB consumes the generated package PackageB, the file test.txt is not copied to its output. That way the transitively referenced PackageA will never work as expected.

Again, with the script Check.ps1, you can see, after build:

=============================================
test.txt has NOT been copied to ProjectConsumingB/bin/Debug/net7.0.
PackageA cannot run.
=============================================

and after publish:

=============================================
test.txt has NOT been copied to ProjectConsumingB/bin/Debug/net7.0/publish.
PackageA cannot run.
=============================================

Expected behavior

I want the file test.txt from PackageA to be transitively copied in the output of the project ProjectConsumingB through the package reference to PackageB when building and publishing ProjectConsumingB.