Main Thread Panicked: Already borrowed uniquely about hecs HOT 2 CLOSED

This was discussed on the gamedev discord, but for posterity: No, concurrent queries with conflicting borrows are not supported. The example works because its borrows don't conflict, because they're shared (aka immutable), whereas you're starting out with a unique (aka mutable) borrow of Transform2D, then trying to get another.

Alternative approaches include:

• Don't use nested queries. As discussed in the README and in the comment just above your link, they're a wasteful solution to the problem of collision detection.
• Don't use a mutable borrow in either query. If you need to make changes in a nested query, accumulate a list of changes to make in a Vec then apply it in a separate pass.

from hecs.

Understood! Thanks for the time.

from hecs.