install/53622: "[: SMALL test, no fallback usage" during amd64 network install

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         53622
>Category:       install
>Synopsis:       "[: SMALL test, no fallback usage" during amd64 network install
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Sep 20 14:25:00 +0000 2018
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date 2018.09.19.07.54.11
>Organization:
>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

When installing NetBSD-current/amd64 over the network by netbooting the
INSTALL kernel (from release/amd64/binary/kernel/netbsd-INSTALL.gz),
the message "[: SMALL test, no fallback usage" appears on
the console multiple times:

  [  24.6598977] boot device: bnx0
  [  24.6899089] root on md0a dumps on md0b
  [  24.7399277] root file system type: ffs
  [  24.7799427] kern.module.path=/stand/amd64/8.99.25/modules
  [  24.8535753] warning: no /dev/console
  Created tmpfs /dev (1638400 byte, 3168 inodes)
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  [: SMALL test, no fallback usage
  erase ^?, werase ^W, kill ^U, intr ^C

The error messages notwithstanding, sysinst starts normally and the
install completes successfully.

>How-To-Repeat:

>Fix: