unexpected/unnecessary `refs` directory in published output of ASP.NET Core application

Steps to reproduce

1. create new ASP.NET Core (.NET Framework) application template in Visual Studio
2. publish a release build

Expected behavior

• The only DLLs included local to the .exe would be third-party libraries loaded as nugget packages

Actual behavior

• There is a refs directory that contains many System.* DLLs, a copy of the application, and the DLL for Razor Tooling
• The refs directory can be removed and the application still runs and Razor pages still render

Environment data

dotnet --info output:

.NET Command Line Tools (1.0.0-preview2-003121)

Product Information:
 Version:            1.0.0-preview2-003121
 Commit SHA-1 hash:  1e9d529bc5

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.14393
 OS Platform: Windows
 RID:         win10-x64

[eerhardt]

If you don’t want this directory published, you can remove:

"preserveCompilationContext": true

from your project.json. But note that removing that setting may completely break your Razor compilation at runtime.

Closing as “by design”.

@pranavkm

[Neutrino-Sunset]

I don’t understand what’s going on here.

“Razor compilation is attempting to use the same refs to compile the view at runtime as the ones that the application used.”

This suggests that there are two separate sets of dependencies.

1. The application’s dependencies.
2. The dependencies used by Razor to compile the view.

But isn’t the code compiling the view contained in the Microsoft.AspNetCore assemblies? And aren’t those assemblies loaded into the application’s app domain? So don’t they have the same dependencies as the application anyway, since they are part of the same application?

Also the assemblies in /refs don’t even look like the actual assemblies they purport to be. E.g. Microsoft.CSharp.dll in/refs is 23k, except that no real Micorsoft.CSharp.dll is actually 23k, the real ones are 1.1MB (Dotnet Core) and 472K (Dotnet Framework).

There is clearly more going on here than meets the eye and I need to understand it as I am designing our first ASP.Net Core application.

Is there a fuller more technical explanation of this somewhere or can someone here explain this please?