I copied your code:
{{ .Page.Store.Add “all_sources” (slice (slice .Destination .Text))}}
it does
Error: error building site: “/home/drm/WEBSITE/content/docs/History/Atlantis.md:1:1”: “/home/drm/WEBSITE/layouts/_default/_markup/render-link.html:22:10”: execute of template failed: template: _default/_markup/render-link.html:22:10: executing “_default/_markup/render-link.html” at <.Page.Store.Add>: error calling Add: cannot append slice of
[]interface {} to slice of interface {}
No difference with Scratch.