better error locations in case of duplicate instances (II)
better error locations in case of duplicate instances (II)

scrotty/frege,sjfloat/frege,sjfloat/frege,mperry/frege,vsts/frege,oppai/frege,ppelleti/frege,scrotty/frege,mperry/frege,vsts/frege,oppai/frege,ppelleti/frege,ppelleti/frege,sjfloat/frege,oppai/frege,vsts/frege,scrotty/frege,mperry/frege