port-evbarm/55521: evbarm-aarch64 testbed hangs during sbin/ifconfig/t_repeated_link_addr test

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

>Number:         55521
>Category:       port-evbarm
>Synopsis:       evbarm-aarch64 testbed hangs during sbin/ifconfig/t_repeated_link_addr test
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-evbarm-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jul 27 15:20:00 +0000 2020
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current
>Organization:
>Environment:
System: NetBSD
Architecture: aarch64
Machine: evbarm
>Description:

The TNF evbarm-aarch64 testbed is currently failing to complete most,
but not quite all ATF test runs because the system under test hangs
at the sbin/ifconfig/t_repeated_link_addr test almost every time.

Log output from a recent hung test run is at

  http://releng.netbsd.org/b5reports/evbarm-aarch64/2020/2020.07.23.16.08.02/test.log

>How-To-Repeat:

>Fix: