As far as I can tell, this is because it's referenced from RxNorm but hasn't been included in the PubChem download yet. So we find an identifier we want to reference, but can't.
My current attempt to fix this looks for non-normalizable identifiers in the drugchemical conflation pairs and then removes them from the pairs -- as long as the rest of the compendium consists only of identifiers we have information about (which it should, since drugchemical conflation is run only after all the individual chemical conflations have been generated), this should be all we need to do:
As far as I can tell, this is because it's referenced from RxNorm but hasn't been included in the PubChem download yet. So we find an identifier we want to reference, but can't.
My current attempt to fix this looks for non-normalizable identifiers in the drugchemical conflation pairs and then removes them from the pairs -- as long as the rest of the compendium consists only of identifiers we have information about (which it should, since drugchemical conflation is run only after all the individual chemical conflations have been generated), this should be all we need to do: