Upgrade to XCode 4.3.2 caused MacPorts builds to fail

The AppStore app on my Lion tells me there is an upgrade available for XCode. I let it download and install the update. Fast forward a few days, and I decide its time I check for updated ports on MacPorts. One sudo port selfupdate, and then a sudo port upgrade outdated later, mercurial fails to build. Looking at the log file reveals that it can't find the compiler.

Belatedly looking at What's New in XCode reveals that there apparently is nothing new in version 4.3.2 (4E2002), as of 4.3, /Developer directory no longer exists.

The same document also points out that command line tools are now optional. I go back and install them and there seems to be no way to tell where they ended up on my system.

I can see there is a llvm-gcc-4.2 in my /usr/bin and the MacPorts log for the failed mercurial build mentions that it could not find /Developer/usr/bin/llvm-gcc-4.2, so go:

sudo mkdir /Developer
sudo mkdir /Developer/usr
sudo ln -s /usr/bin /Developer/usr/bin

Thereafter sudo port upgrade outdated proceeds to happily overheat my MacBook Pro for an hour or so.

Moral of the story: Don't do as I do. Check what's changed first.