install/57987: sysinst refuses to upgrade the booted root partition

[campbell+netbsd%mumble.net@localhost]

>Number:         57987
>Category:       install
>Synopsis:       sysinst refuses to upgrade the booted root partition
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 03 02:35:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
The NetBSD Installation (upgrade)
>Environment:
>Description:
NetBSD in VM with ld4 (unused), ld5 (gpt), dk0@ld5 (efi), dk1@ld5 (netbsd root partition).

# sysinst
a: Installation messages in English
b: Upgrade NetBSD on a hard disk
b: Yes
c: Preconfigured "wedges" dk(4)

Shows these options:

                            ┌──────────────────────┐                            
                            │ Existing "wedges"    │                            
                            │                      │                            
                            │>a: EFI (dk0@ld5)     │                            
                            │ x: Exit              │                            
                            └──────────────────────┘                            

Presumably dk1@ld5 was excluded because of:

    712 	/*
    713 	 * Exclude a disk mounted as root partition,
    714 	 * in case of install-image on a USB memstick.
    715 	 */
    716 	if (is_active_rootpart(state->dd->dd_name,
    717 	    state->dd->dd_no_part ? -1 : 0))
    718 		return true;

https://nxr.netbsd.org/xref/src/usr.sbin/sysinst/disks.c?r=1.95#712
>How-To-Repeat:

>Fix:
Yes, please!

(Ideally we would incorporate a non-interactive upgrade tool, like syspugrade, into base and our releng processes.  But I thought I'd try this built-in approach for now instead of my hand-crufted tar/etcupdate/postinstall that I've been doing for many years, and which I guess I'll keep doing for now.)