Affects Version/s: None
Fix Version/s: None
Inserting facts into a relation that is defined in another namespace, specifically a namespace that has been required but not referred (I don't see the bug if I :use the other namespace).
I've tracked the problem down to this line:
In the facts function, when the relation index gets resolved, the namespace is not taken into account,
index (var-get (resolve (index-sym (.name rel) arity o)))
as it is when resolving the relation set.
rel-set (var-get (ns-resolve rel-ns (set-sym (.name rel) arity)))
Using ns-resolve, with rel-ns, seems to fix the issue for me.
index (var-get (ns-resolve rel-ns (index-sym (.name rel) arity o)))