perl5.12 won't compile with Xcode 4

[christopher.hearn@…]

After upgrading to Xcode4, perl5.12 won't compile:

$ sudo port -v upgrade outdated ---> Configuring perl5.12 First let's make sure your kit is complete. Checking... Would you like to see the instructions? [n] ........ Install any extra modules (y or n)? [n] Directory for the main Perl5 html pages? (~name ok) [none] Directory for the Perl5 module html pages? (~name ok) [none] Do you want to install perl as /usr/bin/perl? [n] Checking for GNU C Library... Shall I use /usr/bin/nm to extract C symbols from the libraries? [y] I can't seem to find your C library. I've looked in the following places:

............

And it hangs at that point.