no authentication methods compiled ?

[Todd C. Miller]

Somehow, WITHOUT_PASSWD was getting defined in config.h
If you comment out:

#define WITHOUT_PASSWD 1

Sudo should work properly for you.  It looks like this is a side
effect of using "--disable-pam".  You don't need to specify
--disable-pam since it is off by default.  However, I don't see
the bug in configure that would cause this nor can I reproduce
the problem myself (using 1.6.3p4)

 - todd