Migration questions

[Stephen Langer]

Hi --

I upgraded my Mac at work from 10.7 to 10.9 yesterday.  Xcode was still 
being downloaded when I left in the evening.  When I got home I 
downloaded and installed macports using the migration instructions, 
except that I installed it using the 'installer' command instead of the 
gui, since I was logged in remotely.  I ran xcode-select --install and 
agreed to the license.  Everything went smoothly, except that later 
macports issued warnings about not finding the xcode command line tools 
for each port that I installed although all of the ports seemed to 
install properly (there were no failure messages).

When I got to work this morning I saw that "xcode-select --install" 
raises a dialog box that I hadn't seen (being logged in remotely) and 
that the command line tools probably weren't installed after all.  So 
either none of the ports I installed were built from source, or they 
were built using the old versions of the command line tools.

How does macports know whether the command line tools are installed? 
Would it have noticed if the tools were merely out of date?

Should I reinstall the ports that were built from source?  How can I 
find out which ones those were?   I'd rather not reinstall everything, 
but I could do that if necessary.

I'm asking because I program that I'm working on is behaving strangely 
on this computer, but not on another one also running 10.9.

Thanks,
       Steve