Failed to download the package from https://github.com/klayoutmatthias/xsection.git/tags/1.3/src.
There needs to be a file called 'grain.xml' below this URL. It needs to have the XML format of a KLayout package definition file.
This URL will be used for the package file: https://github.com/klayoutmatthias/xsection.git/tags/1.3/src/grain.xml.