about 4 days now trying to solve it 
plz I need it urgent
every time I got that message:
**Initial task interrupted by exception
Message: Access to the path "/Users/Nemo/.config/xbuild" is denied.
Exception type: System.UnauthorizedAccessException
at Xamarin.Web.Installer.TasksManager.DetectComponents () [0x00097] in /Users/builder/data/lanes/5758/e32e17ec/source/installer/Xamarin.Web.Installer/TasksManager.cs:297**