Play nice with multi-platform development (errors with GDK package on macOS)

[sttz]

When importing the package on macOS, I'm getting following errors when it tries to access the registry through Window-specific APIs.

I'm aware GDK is not supported on macOS but our projects targets multiple platforms and needs to run on macOS. The GDK package should check if it's not running in the Windows Unity editor and disable everything that relies on Windows-specific APIs and functionality.

Errors in macOS Unity editor

Failed to get key: Advapi32.dll assembly:<unknown assembly> type:<unknown type> member:(null)
UnityEngine.Debug:LogError (object)
Microsoft.GameCore.Utilities.GdkUtilities/RegUtil:GetRegKey (uint,string,string) (at Assets/GDK-Tools/Source/Utilities/GdkUtilities.cs:236)
Microsoft.GameCore.Utilities.GdkUtilities:get_GdkVersion () (at Assets/GDK-Tools/Source/Utilities/GdkUtilities.cs:37)
Microsoft.GameCore.Utilities.GdkUtilities:PullGdkDlls () (at Assets/GDK-Tools/Source/Utilities/GdkUtilities.cs:152)
Microsoft.GameCore.Tools.GdkPlugin:.cctor () (at Assets/GDK-Tools/Source/Editor/GdkPlugin.cs:20)
UnityEditor.EditorAssemblies:ProcessInitializeOnLoadAttributes (System.Type[]) (at /Users/bokken/build/output/unity/unity/Editor/Mono/EditorAssemblies.cs:126)

System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.
Parameter name: length
  at System.String.Substring (System.Int32 startIndex, System.Int32 length) [0x0004c] in <b476499a37ba4db68de311f404f49770>:0 
  at Microsoft.GameCore.Utilities.GdkUtilities.PullGdkDlls () [0x0002f] in Assets/GDK-Tools/Source/Utilities/GdkUtilities.cs:157 
  at Microsoft.GameCore.Tools.GdkPlugin..cctor () [0x00000] in Assets/GDK-Tools/Source/Editor/GdkPlugin.cs:20 
UnityEditor.EditorAssemblies:ProcessInitializeOnLoadAttributes (System.Type[]) (at /Users/bokken/build/output/unity/unity/Editor/Mono/EditorAssemblies.cs:134)

No MicrosoftGame.Config found. Please re-import this plugin.
UnityEngine.Debug:LogError (object)
Microsoft.GameCore.Utilities.GdkUtilities:get_GameConfigPath () (at Assets/GDK-Tools/Source/Utilities/GdkUtilities.cs:131)
Microsoft.Xbox.Gdk:OnValidate () (at Assets/GDK-Tools/Source/Scripts/Gdk.cs:149)

[edwarduwms]

Thank you, we will take your feedback into consideration for the next releases.