install/54871: No oportunity to edit MBR partitions table for USB stick on system installation

[guest01%vp.pl@localhost]

>Number:         54871
>Category:       install
>Synopsis:       No oportunity to edit MBR partitions table for USB stick on system installation
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jan 18 15:10:00 +0000 2020
>Originator:     guest01
>Release:        http://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-9/202001160600Z/images/NetBSD-9.0_RC1-amd64-install.img.gz
>Organization:
-
>Environment:
NetBSD  9.0_RC1 NetBSD 9.0_RC1 (GENERIC) #0: Thu Jan  9 17:18:43 UTC 2020  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
When you install NetBSD 9.0_RC1 on USB stick and you have set geometry there is no oportunity to edit MBR partiton table. Sysinst goes to setup NetBSD partitions.
NetBSD 8.0 allows edit MBR partion table for USB stick.
>How-To-Repeat:
Boot computer with NetBSD 9.0_RC1 installation image and then select:
1. Install NetBSD to hard disk
2. Shall we continue? Yes
3. On which disk do you want to install NetBSD?
   b: sd0 (929M)
4. Sysinst could not automatically determine the BIOS geoemtry of the disk.
   The phisical geometry is 471 cylinders 16 sectors 63 heads.
   You will be prompted for the geometry. Please enter the number of sectors per track (maximum 63) and the number of heads (maximum 256) that the BIOS uses to access the disk. The number of cylinders will be calculated from the disk size.
   sectors [63]: enter
   heads   [16]: enter

There is not oportunity to edit MBR partition table here which was in NetBSD 8.0. Next screen will be about NetBSD partitions.
>Fix: