[OpenIndiana-discuss] Why is user logged into `/'

[Harry Putnam]

In two separate installs of b 147.. I find that my user gets logged
into `/' on login.

home is mounted normally:

mount |grep home

  /export/home on rpool/export/home
  read/write/setuid/devices/nonbmand/exec/xattr/atime/dev=950008 on Thu
  Dec 2 19:06:19 2010
  
  /export/home/reader on rpool/export/home/reader
  read/write/setuid/devices/nonbmand/exec/xattr/atime/dev=950009 on Thu
  Dec 2 19:06:19 2010
  
  /home/reader on /export/home/reader
  read/write/setuid/devices/dev=950009 on Thu Dec 2 19:06:37 2010

And its obvious from the values of PS1 and PS4 that the ~/.bashrc has
been read but the shell opens at `/'.

/etc/passwd clearly shows user at /home/reader

On login user knows the value of $HOME... an echo shows:
/home/reader

If I `su -'   to root, root is also logged in to `/'.. an echo from
roots' shell of $HOME shows /root, /etc/passwd shows /root

Since root is part of `/' there is no question of its being mounted.

So what is the likely cause?  Or how can I debug it.  The usual things
like /etc/passwd that dictate such things seem to point to the normal
places yet logging in does not seem to pay any attention to that.