strictMap in updateIdInfos probably doesn't do what was intended
updateModetailsIdInfos there is a call to
strictMap which doesn't actually force the right thing because the result of applying the function
updateGlobalIds is stored inside a lazy field in a
Rule. Therefore the value is only forced to the outermost rule which leaves a THUNK in the rule.
In general there are many many long-lived thunks due to
updateModDetailsIdInfos because of the lazy knot-tying. It seems like a place which could easily retain
TypeEnvs past their expiry date.