Home: PackageReference: Need control over the selection for individual .dlls

[KirillOsenkov]

Details about Problem

NuGet product used (NuGet.exe | VS UI | Package Manager Console | dotnet.exe):
MSBuild 15.3 elements.

VS version (if appropriate):
15.3 or newer

Detailed repro steps so we can see the same problem

I don't see a way to control whether the .dll from PackageReference gets copied to output or not.

Additionally, if I have ProjectA with a PackageReference, and ProjectB referencing ProjectA, I want to make sure that when ProjectB builds, the .dll inherited transitively from ProjectA doesn't get copied to output (but I want it to get copied for ProjectA, and they have different output directories).

There needs to be a way to control this.

[PatoBeltran]

@nkolev92 can you please take a look at this?

[nkolev92]

@KirillOsenkov
If I understand your scenario correctly
<PrivateAssets>all</PrivateAssets> should do it.

https://docs.microsoft.com/en-us/nuget/consume-packages/package-references-in-project-files#controlling-dependency-assets

[KirillOsenkov]

Not quite.

In non-SDK-style projects, set the <CopyNuGetImplementations>false</CopyNuGetImplementations> to not copy the binaries from the referenced packages to output. This also applies to transitively "inherited" packages from PackageReference elements in referenced projects.

In SDK-style projects there's a similar property: <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>

I'm also looking for a way to copy some .dlls to output, but not others. For instance, https://www.nuget.org/packages/Microsoft.VisualStudio.Composition/15.3.38 - I want to copy Microsoft.VisualStudio.Composition.dll to output, but I don't want any of the satellite resource assemblies. I wasn't able to find a way to do that.

[KirillOsenkov]

Also with PrivateAssets the problem is that I do want a reference to the .dll added to my project, but not copied to output. With CopyNuGetImplementations=false I can just rely on the inherited transitive package references. However to use PrivateAssets I need to duplicate the PackageReferences from ProjectA in ProjectB, which defeats the purpose of transitivity.

[rohit21agrawal]

ExcludeAssets=runtime does that, but it will apply to every dll in the lib folder

[nkolev92]

Clear.
Currently we don't have any type of granular control of package assets of the same category.
//cc
@emgarten

[rrelyea]

Does @rohit21agrawal's proposal help? (excludeassets runtime)

[KirillOsenkov]

Nope, not quite, see my description above.

[mungojam]

Interesting, I think I'm after the opposite (roslyn 22095) where transitive .net DLLs are copied to output, but not included as references (or at least their APIs are not exposed).

[kirsan31]

Very needed, to deal with not correctly configurated nugget packages. For example, for now Microsoft.Web.WebView2 copies all dll to output in any case:

Microsoft.Web.WebView2.Core.dll
Microsoft.Web.WebView2.WinForms.dll
Microsoft.Web.WebView2.Wpf.dll

But in WinForms we absolutely no need of Microsoft.Web.WebView2.Wpf.dll...
Wood be useful if ExcludeAssets can handle names for input, for example: ExcludeAssets="Native;Microsoft.Web.WebView2.Wpf.dll;Microsoft.Web.WebView2.WinForms.dll"

[KirillOsenkov]

I've found that you can manually control which .dlls to reference and which .dlls to copy to output from a NuGet package if you turn off all assets on the PackageReference:

<PackageReference Include="Foo.MyPackage" Version="1.0.0" ExcludeAssets="all" GeneratePathProperty="true" />

and then manually reference the .dlls you need:

<Reference Include="$(PkgFoo_MyPackage)\lib\net45\CopyThis.dll">
  <Private>true</Private>
</Reference>
<Reference Include="$(PkgFoo_MyPackage)\lib\net45\DontCopyThis.dll">
  <Private>false</Private>
</Reference>
<None Include="$(PkgFoo_MyPackage)\lib\net45\CopyThisButDontReference.dll">
  <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</None>

Note the usage of GeneratePathProperty on the PackageReference to generate the Pkg*** property, where the package name is prefixed with Pkg and dots replaced with underscores.

[kirsan31]

@KirillOsenkov very cool workaround - thank you! I see here only 3 drawback:

1. You need to know exactly the version of the framework from the package. E.g. _\lib\ netcoreapp3.0 \CopyThis.dll_. And if it will changed - all stop work :(
2. xml docs will be copied to Release dir too.
3. I think individual exclude will be more helpful than individual include overall.