The NetBSD-current/i386 build is working again. The following commits were made between the last failed build and the successful build:
2019.09.12.14.28.08 martin src/sys/arch/x86/acpi/acpi_machdep.c,v 1.28 2019.09.12.15.17.08 bad src/sys/rump/listsrcdirs,v 1.40 Log files can be found at: http://releng.NetBSD.org/b5reports/i386/commits-2019.09.html#2019.09.12.15.17.08