Conditions for new, additional parentConstraint?


Hey there,
I have two files that seem to be similar but are behaving differently.
I have a space switching tool that allows animators to add or remove drivers (targets) with matching, etc. In every case but one, adding or removing drivers to constraints works fine – the targets are added and removed from the specific constraint. In this one file, though, if I try to add a target using the specific Python constraint call from Maya (pointConstraint, parentConstraint, etc.) a new constraint is created instead of using the one already there.
I’ve tried debugging but no mater what I’ve done up to this point, a new constraint is created.
I know I’ve run into this before, years ago, but I can’t remember what node state would cause a new constraint to be created instead of piggybacking off of an existing constraint.


Hey, look at that. Closing down all sessions of Maya and opening it up again seems to have fixed things.
Way weird. I thought I’d already tried that. Oh, well.