sdk: Can't install global tool

Steps to reproduce

$ dotnet tool install -g Nuke.GlobalTool --source-feed C:\code\nuke\output --version 1.0.0

Package file exists as Nuke.GlobalTool.1.0.0.nupkg.

Actual behavior

Failed to install tool package 'nuke.globaltool': Access to the path 'C:\Users\matthias.koch\.dotnet\tools\.store\.stage\fpn34yfr.xj2' is denied.
Tool 'nuke.globaltool' failed to install. This failure may have been caused by:
* You are attempting to install a preview release and did not use the --version option to specify the version.
* A package by this name was found, but it was not a .NET Core tool.
* The required NuGet feed cannot be accessed, perhaps because of an Internet connection problem.
* You mistyped the name of the tool.

Environment data

dotnet --info output:

.NET Core SDK (reflecting any global.json):
 Version:   2.1.300-rc1-008673
 Commit:    f5e3ddbe73

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.16299
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\2.1.300-rc1-008673\

Host (useful for support):
  Version: 2.1.0-rc1
  Commit:  eb9bc92051

.NET Core SDKs installed:
  1.1.8 [C:\Program Files\dotnet\sdk]
  2.1.4 [C:\Program Files\dotnet\sdk]
  2.1.101 [C:\Program Files\dotnet\sdk]
  2.1.104 [C:\Program Files\dotnet\sdk]
  2.1.105 [C:\Program Files\dotnet\sdk]
  2.1.300-rc1-008673 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.0-rc1-final [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.0-rc1-final [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 1.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.1.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.0-rc1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]