verifying your macports

[Alexy Khrabrov]

After the scare of spurious libgcc getting in the way, I'm wondering  
how can we verify our setups.  This is when rpm-style verification  
and binary distros shine.  Sure you can compile stuff, but what if  
some crap got into your PATH -- beginning with a wrong gcc?  What if  
some other crap got into LDFLAGS or DYLD_LIBRARY_PATH or whatever?   
What tools are there to verify

-- completeness of each port
-- proper chain of dependencies of each port
-- checking that no port depends on any package not built by the  
ports -- e.g., nothing outside /opt/local
-- that each executable in /opt/local/bin will load
-- what else?

Cheers,
Alexy