The NetBSD-current/i386 build is working again. The following commits were made between the last failed build and the successful build:
2017.06.19.20.10.18 christos src/etc/Makefile,v 1.431 2017.06.19.20.12.34 christos src/external/bsd/elftosb/usr.sbin/elftosb/Makefile,v 1.5 2017.06.19.20.12.34 christos src/external/bsd/mdocml/bin/mandoc/Makefile,v 1.12 2017.06.19.20.52.20 mlelstv src/sys/dev/scsipi/scsipi_base.c,v 1.177 Log files can be found at: http://releng.NetBSD.org/b5reports/i386/commits-2017.06.html#2017.06.19.20.52.20