The NetBSD-current/i386 build is working again. The following commits were made between the last failed build and the successful build:
2017.04.08.01.29.31 kamil src/doc/CHANGES,v 1.2269 2017.04.08.02.02.30 kamil src/sys/arch/i386/include/ptrace.h,v 1.19 Log files can be found at: http://releng.NetBSD.org/b5reports/i386/commits-2017.04.html#2017.04.08.02.02.30