I can&#39;t seem to recall why, but last week a port I was trying to install depended on the heimdal port. So I installed it and went on my merry way ... until today that is, when I ended up doing this for:<br><br>$ sudo su - postgres81
<br><br>Whoops! That &quot;su&quot; is not the &quot;su&quot; you might be thinking of. That &quot;su&quot; is:<br><br>/path/to/macports/bin/su as in /opt/local/bin/su<br><br>installed by the heimdal port.<br><br>Yikes! More than one su to choose from? Could be scary for the unaware!
<br><br>The problem is that by default the Heimdal &quot;su&quot; wants to use Kerberos so it stops and asks you ( even though you&#39;ve first sudo&#39;ed to root using Apple&#39;s &quot;sudo&quot;) what is the password for the user you&#39;re su&#39;ing to (in the case above postgres81). If you don&#39;t have kerberos running then it will complain but will then revert to your local NetInfo domain (or I presume Open Directory or LDAP) for accessing passwords. 
<br><br>Regarding not having kerberos running, no problem, the Heimdal man page says you can disable the default kerberos check with a &quot;-K&quot; but that would then mean that you&#39;d have to do &quot;su -K postgresql81&quot;, and that would mean you&#39;d have to manually modify&nbsp; startup scripts such as that used by the postgres81 user for firing up PostgreSQL 
8.1.x that its launchd plist in /Library/LaunchDaemons points to. It might be worth the extra manual work but it probably depends on your needs. Yeah, there are other ways to force use of /usr/bin/su but anyway, the Heimdal cloaking of su threw me off today so I thought I&#39;d warn others ahead of time in case there are some ports that depend on Heimdal and you end up installing (without deactivating) Heimdal in the process.
<br><br>BTW, absolutely no offense meant toward&nbsp; Landon who maintains the Heimdal MacPort.<br><br>Best regards,<br><br>T.M.