install/47195: NetBSD 6.0 (i386) install from/to USB fails

[dnied%tiscali.it@localhost]

>Number:         47195
>Category:       install
>Synopsis:       NetBSD 6.0 (i386) install from/to USB fails
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Nov 15 11:10:00 +0000 2012
>Originator:     Dario Niedermann
>Release:        6.0
>Organization:
>Environment:
Linux localhost 2.6.24.5-smp #1 SMP Wed Apr 30 13:18:13 CDT 2008 i686 AMD 
Turion(tm) 64 Mobile Technology MK-36 AuthenticAMD GNU/Linux

>Description:
I've been trying to install NetBSD from a USB stick to the same USB
stick containing the installer. This looked feasible, since sysinstall
at some early step says "if you booted from USB you can remove media
now", but this doesn't seem to be true.

In fact, if media is removed when sysinstall advises to (and then
reinserted, because I want to install onto that same stick) the blue
screen is immediately replaced by a green-on-black console. When the
screen is refreshed with ^L, the installer freezes.

If media is not removed, minimal installation to sd0 proceeds and
seems to be OK: partitioning (correct size is reported), binary set
download and install via FTP, everything looks all right... until
reboot, where I find out that the USB stick wasn't partitioned as
instructed and it's not bootable (for lack of /boot, a message says).

I'm posting this to the bugs ML because:

1) sysinstall says boot media can be removed, but doing so freezes
   the installer;

2) in case boot media is not removed, sysinstall gives the false
   impression that everything is going well, but the result is an
   unbootable USB stick

3) the procedure resulted in a waste of time, bandwith (retrying &
   redownloading sets) and a frustrating user experience.

Hoping this is useful for improving the installer and/or the
documentation.

Best regards,
DN

>How-To-Repeat:
The image used is 'NetBSD-6.0-i386-install.img', and it was written
to the USB stick with 'cat NetBSD-6.0-i386-install.img >/dev/sda'
on a Linux system. This produced a bootable USB stick.

>Fix: