dotnet build (1.0.0-rc2-002543) - An item with the same key has already been added. Key: System.IO.Compression

Steps to reproduce

Clone https://github.com/Humanizr/Humanizer.git and checkout the dev branch. Checkout this commit: https://github.com/Humanizr/Humanizer/commit/c42e2cd03356824e7a68f93753c22c01143393ac go to src\Humanizer and run restore on Humanizer and Humanizer.Tests.Dotnet in src\Humanizer.Tests.DotNet, run dotnet build

Expected behavior

Build should succeed.

Actual behavior

Build fails with An item with the same key has already been added. Key: System.IO.Compression

Environment data

dotnet --info output: .NET Command Line Tools (1.0.0-rc2-002543)

Product Information: Version: 1.0.0-rc2-002543 Commit Sha: 38d0c28a1e

Runtime Environment: OS Name: Windows OS Version: 10.0.14332 OS Platform: Windows RID: win10-x64

[brthor]

Okay, it’s looking like we’ll need to debug.

cc @piotrpMSFT This seems pretty weird, I think we should consider this for RC2.

[clairernovotny]

Might this have something to do with xproj -> csproj refs?

 "Humanizer/2.1.0": {
      "type": "project",
      "path": "../Humanizer/project.json"
    },
    "Humanizer.DotNet/2.1.0": {
      "type": "project",
      "path": "../Humanizer/project.json",
      "msbuildProject": "../Humanizer/Humanizer.DotNet.xproj"
    }

This is wrong. Humanizer.DotNet.xproj uses project.json. The csproj Humanizer uses Humanizer.project.json and both should not be picked up here.