Snap!con collection contains v7 projects.
At least
https://snap.berkeley.edu/project?user=spaceelephant&project=chacha%20cipher
https://snap.berkeley.edu/project?user=bh&project=dev%20color%20library
https://snap.berkeley.edu/project?user=bh&project=macros%20v0.1
https://snap.berkeley.edu/project?user=spaceelephant&project=raycasting%20in%20BIG%20PIXEL%20library%20SnapCon%202021
Umm I don't think this is a bug, exactly. I suppose we could make the site look at the header of a project it's about to load, and select the appropriate version of Snap! to run it in, but this is meant to be only a short-term issue.
So maybe put a complete link to Dev version in the description