https://ci.swift.org/job/oss-swift-incremental-RA-linux-ubuntu-16_10/416/consoleFull#-1996075066ee1a197b-acac-4b17-83cf-a53b95139a76 shows a build failure I'm reproducing locally. Rolling back to 4caa7532f923e759093df9227df20a36a002d28d (before recent indexing-related changes) fixes it for me. -- -Dave