To give you some more information:

It seems that auth/changeuser hangs in reading from /dev/cons:
cpu% ps  | grep changeuser
bootes         2276    0:00   0:00       72K Pread    changeuser
cpu% acid 2276
/proc/2276/text:386 plan 9 executable
/sys/lib/acid/port
/sys/lib/acid/386
acid: stk()
pread()+0x7 /sys/src/libc/9syscall/pread.s:5
read(fd=0x4,buf=0xdfffef09,n=0x1)+0x2f /sys/src/libc/9sys/read.c:7
readln(prompt=0xe31c,raw=0x1,line=0xdfffef09,len=0x20)+0xcf /sys/src/cmd/auth/lib/readln.c:84
getpass(pass=0xdfffef09,confirm=0x1,key=0xdfffef49,check=0x1)+0x39 /sys/src/cmd/auth/lib/readln.c:18
main(argv=0xdfffefa8,argc=0x1)+0x1bf /sys/src/cmd/auth/changeuser.c:65
_main+0x31 /sys/src/libc/386/main9.s:16
acid: 

Fd 4 is /dev/cons in this case...

This happens when doing any of the following:

drawterm to the machine as some user, then cpu'ing to localhost, then mounting the served root and calling auth/changeuser.

drawterm to the machine as bootes, omitting the cpu call and proceed as above

This all happens with auth/debug as well, which has been known to work with drawterm to my knowledge.

Kind regards,

Christian

-- 
You may use my gpg key for replies:
pub  1024D/47F79788 2005/02/02 Christian Kellermann (C-Keen)