port-arm/54490: abort trap in sysinst for aarch64 netbsd-current 2019-08-23

[mujo%sdf.org@localhost]

>Number:         54490
>Category:       port-arm
>Synopsis:       abort trap in sysinst for aarch64 netbsd-current 2019-08-23
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-arm-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Aug 26 22:15:00 +0000 2019
>Originator:     Ian
>Release:        NetBSD-current 2019-08-23
>Organization:
>Environment:
NetBSD  9.0_BETA NetBSD 9.0_BETA (GENERIC64) #0: Fri Aug 23 04:24:00 UTC 2019  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/evbarm/compile/GENERIC64 evbarm
>Description:
assertion "info->nat_type != NULL" failed: file "/usr/src/usr.sbin/sysinst/arch/evbarm/../../mbr.c", line 1938, function "mbr_add_part" [1]   Abort trap              sysinst

>How-To-Repeat:
Boot netbsd generic aarch64 image from invisible.ca on allwinner a53-cortex (Olimex Teres laptop), run `sysinst`, select "Other System", "Install to Hard disk", select embedded mmc (ld0), and "Use default partition sizes" then sysinst reliably crashes with the above error message.
>Fix:
Just a guess, but aarch64 systems do not use an mbr.