install/59573: 11.0_BETA install leaves behind /etc/rc.conf.bak.* files

[sr%genyosha.net@localhost]

>Number:         59573
>Category:       install
>Synopsis:       11.0_BETA install leaves behind /etc/rc.conf.bak.* files
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Aug 04 22:30:00 +0000 2025
>Originator:     Steve Rikli
>Release:        11.0_BETA
>Organization:
>Environment:
NetBSD 11.0_BETA (GENERIC) #0: Fri Aug  1 17:05:55 UTC 2025  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/i386/compile/GENERIC
>Description:
Freshly-installed NetBSD-11 apparently creates /etc/rc.conf.bak.* files but doesn't clean up before exiting sysinst:

vm07# uname -v
NetBSD 11.0_BETA (GENERIC) #0: Fri Aug  1 17:05:55 UTC 2025  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC
vm07# ls -la /etc/rc.conf /etc/rc.conf.bak.*
-rw-r--r--  1 root  wheel  608 Aug  4 21:12 /etc/rc.conf
-rw-------  1 root  wheel    0 Aug  4 21:11 /etc/rc.conf.bak.0axBdV

vm08# uname -v
NetBSD 11.0_BETA (GENERIC) #0: Fri Aug  1 17:05:55 UTC 2025  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/i386/compile/GENERIC
vm08# ls -la /etc/rc.conf /etc/rc.conf.bak.*
-rw-r--r--  1 root  wheel  608 Aug  4 20:58 /etc/rc.conf
-rw-------  1 root  wheel    0 Aug  4 20:56 /etc/rc.conf.bak.GuyiFF

The amd64 install is from 20250801170555Z
The i386  install is from 20250801170555Z

There's no apparent harm from the .bak file, it's just untidy.
>How-To-Repeat:
Systems were installed by booting netbsd-INSTALL.gz from the same build as noted for the sets, and using sysinst normally.
>Fix: