error building FSharp.Core

[Wael El Oraiby]

on Windows, I get the following error when building using build.cmd:

Time Elapsed 00:00:01.79
  Restoring packages for D:\Projects\dotnet-js\src\FSharp.Core\FSharp.Core.fsproj...
  Generating MSBuild file D:\Projects\dotnet-js\src\FSharp.Core\obj\FSharp.Core.fsproj.nuget.g.props.
  Generating MSBuild file D:\Projects\dotnet-js\src\FSharp.Core\obj\FSharp.Core.fsproj.nuget.g.targets.
  Writing lock file to disk. Path: D:\Projects\dotnet-js\src\FSharp.Core\obj\project.assets.json
  Restore completed in 485.64 ms for D:\Projects\dotnet-js\src\FSharp.Core\FSharp.Core.fsproj.

  NuGet Config files used:
      C:\Users\Wael\AppData\Roaming\NuGet\NuGet.Config
      C:\Program Files (x86)\NuGet\Config\Microsoft.VisualStudio.Offline.config

  Feeds used:
      https://api.nuget.org/v3/index.json
      C:\Program Files (x86)\Microsoft SDKs\NuGetPackages\
Microsoft (R) Build Engine version 15.1.1012.6693
Copyright (C) Microsoft Corporation. All rights reserved.

C:\Program Files\dotnet\sdk\1.0.4\Sdks\Microsoft.NET.Sdk\build\Microsoft.NET.Sdk.DefaultItems.targets(165,5): error : Duplicate 'Compile' items were included. The .NET SDK includes 'Compile' items from your project directory by default. You can either remove these items from your project file, or set the 'EnableDefaultCompileItems' property to 'false' if you want to explicitly include them in your project file. For more information, see https://aka.ms/sdkimplicititems. The duplicate items were: 'array.fs'; 'array.fsi'; 'array2.fs'; 'array2.fsi'; 'array3.fs'; 'array3.fsi'; 'collections.fs'; 'collections.fsi'; 'event.fs'; 'event.fsi'; 'fslib-extra-pervasives.fs'; 'fslib-extra-pervasives.fsi'; 'Linq.fs'; 'Linq.fsi'; 'list.fs'; 'list.fsi'; 'local.fs'; 'local.fsi'; 'map.fs'; 'map.fsi'; 'MutableTuple.fs'; 'nativeptr.fs'; 'nativeptr.fsi'; 'option.fs'; 'option.fsi'; prim-types-prelude.fs'; 'prim-types-prelude.fsi'; 'prim-types.fs'; 'prim-types.fsi'; 'printf.fs'; 'printf.fsi'; 'QueryExtensions.fs'; 'quotations.fs'; 'quotations.fsi'; 'reflect.fs'; 'reflect.fsi'; 'result.fs'; 'result.fsi'; 'seq.fs'; seq.fsi'; 'seqcore.fs'; 'seqcore.fsi'; 'set.fs'; 'set.fsi'; 'SI.fs'; 'string.fs'; 'string.fsi' [D:\Projects\dotnet-js\srcFSharp.Core\FSharp.Core.fsproj]

Build FAILED.

C:\Program Files\dotnet\sdk\1.0.4\Sdks\Microsoft.NET.Sdk\build\Microsoft.NET.Sdk.DefaultItems.targets(165,5): error : Duplicate 'Compile' items were included. The .NET SDK includes 'Compile' items from your project directory by default. You can either remove these items from your project file, or set the 'EnableDefaultCompileItems' property to 'false' if you want to explicitly include them in your project file. For more information, see https://aka.ms/sdkimplicititems. The du
plicate items were: 'array.fs'; 'array.fsi'; 'array2.fs'; 'array2.fsi'; 'array3.fs'; 'array3.fsi'; 'collections.fs'; 'collections.fsi'; 'event.fs'; 'event.fsi'; 'fslib-extra-pervasives.fs'; 'fslib-extra-pervasives.fsi'; 'Linq.fs'; 'Linq.fsi'; 'list.fs'; 'list.fsi'; 'local.fs'; 'local.fsi'; 'map.fs'; 'map.fsi'; 'MutableTuple.fs'; 'nativeptr.fs'; 'nativeptr.fsi'; 'option.fs'; 'option.fsi'; 'prim-types-prelude.fs'; 'prim-types-prelude.fsi'; 'prim-types.fs'; 'prim-types.fsi'; 'printf.fs'; 'printf.fsi'; 'QueryExtensions.fs'; 'quotations.fs'; 'quotations.fsi'; 'reflect.fs'; 'reflect.fsi'; 'result.fs'; 'result.fsi';'seq.fs'; 'seq.fsi'; 'seqcore.fs'; 'seqcore.fsi'; 'set.fs'; 'set.fsi'; 'SI.fs'; 'string.fs'; 'string.fsi' [D:\Projects\dotnet-js\src\FSharp.Core\FSharp.Core.fsproj]
    0 Warning(s)
    1 Error(s)

Time Elapsed 00:00:00.25
---
Build failed

[Wael El Oraiby]

After upgrading to .net core 2.0, I no longer have this issue. closing it...