Returns the package root of the current isolate, if any.
If the isolate is using a packageMap, this getter returns null
,
otherwise it returns the package root - a directory that package
URIs are resolved against.
Returns the package root of the current isolate, if any.
If the isolate is using a packageMap, this getter returns null
,
otherwise it returns the package root - a directory that package
URIs are resolved against.