E086: A reference to a local variable can't leave the function

A function’s local variables live only until it returns; then that memory is reused. A reference (&T) into it would keep pointing at the reused memory – a “dangling” reference – so Turf refuses to let one escape: not as the return value, not stored into a list, not stored into a struct that outlives the call.

struct Node { val: int }fn make(): &Node {    mut n: Node = Node::default();    n.val = 42;    return &n;                 // n is gone when make() returns}

To hand a value back, copy it onto the heap with heap(...). That copy is managed for you and lives as long as anything refers to it:

fn make(): &Node {    mut n: Node = Node::default();    n.val = 42;    return heap(n);}

A reference you received as a parameter is fine to return or store – it already outlives this function. Only references into this function’s own locals are the problem.

Run turf --explain E086 in a terminal to read this again.