install/59752: crash in sysinst installing 11-BETA

[riz%NetBSD.org@localhost]

>Number:         59752
>Category:       install
>Synopsis:       Crash in sysinst installing NetBSD 11.0_BETA
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Nov 10 18:10:00 +0000 2025
>Originator:     riz%NetBSD.org@localhost
>Release:        NetBSD 11.0_BETA
>Organization:
	
>Environment:
System: NetBSD  11.0_BETA NetBSD 11.0_BETA (GENERIC) #0: Tue Oct 28 15:00:36 UTC 2025  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
	When trying to install to the booted SSD, sysinst crashes when "Use default partition sizes"
	is chosen.
>How-To-Repeat:
	This may be a "don't do that" situation, but a crash is less than ideal.

	I booted a USB SSD with the install image on it, intending to install to the
	same disk:

[     5.740742] sd0: 465 GB, 476940 cyl, 64 head, 32 sec, 512 bytes/sect x 976773168 sectors
[     5.840088] sd0: fabricating a geometry
[     6.070087] sd0: GPT GUID: dbe14200-b40e-11f0-8000-000000000000
[     6.080088] dk0 at sd0: "EFI system", 262144 blocks at 2048, type: msdos
[     6.158654] dk1 at sd0: "NBImgRoot", 4853760 blocks at 264192, type: ffs
[     7.890086] boot device: sd0[     5.690290] sd0: fabricating a geometry

	When installing, I chose "Install NetBSD to hard disk", then selected sd0 for
the install.  (sd0 (466G, PSSD T7) was the menu selection). The geometry was fine,
so at the "What would you like to do?" menu, I chose "c: Use default partition sizes"
and ... Boom:

          â??assertion "parts->num_part == 0" failed: file "/usr/src/usr.sbin/sysinst/arch/amd64/../../bsddisklabel.c", line 1738, function "replace_by_default"ons                            â??
[1]   Abort trap (core dumped) ${cmd} different partitions (not GPT) â??
          â?? x: Cancel                                                â??
To return to the installer, quit this shell by typing 'exit' or ^D.â??â??â??


>Fix:
	none given - I assume I'll be able to work around this, but the crash isn't great.