Mercurial @ Failed to install after upgrading Xcode 4.3

[r91921080@…]

OS: 10.7.3 Xcode: 4.3

$ sudo port -v install mercurial
--->  Computing dependencies for mercurial.
--->  Building mercurial
running build
running build_mo
running build_ext
building 'mercurial.base85' extension
/usr/bin/clang -DNDEBUG -g -O3 -Wall -Wstrict-prototypes -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c mercurial/base85.c -o build/temp.macosx-10.7-x86_64-2.7/mercurial/base85.o
/Developer/usr/bin/clang -bundle -undefined dynamic_lookup -L/opt/local/lib build/temp.macosx-10.7-x86_64-2.7/mercurial/base85.o -o build/lib.macosx-10.7-x86_64-2.7/mercurial/base85.so
unable to execute /Developer/usr/bin/clang: No such file or directory
error: command '/Developer/usr/bin/clang' failed with exit status 1
shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_devel_mercurial/mercurial/work/mercurial-2.1" && /opt/local/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7 setup.py --no-user-cfg build " returned error 1
Error: Target org.macports.build returned: shell command failed (see log for details)
Warning: the following items did not execute (for mercurial): org.macports.activate org.macports.build org.macports.destroot org.macports.install
Log for mercurial is at: /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_devel_mercurial/mercurial/main.log
Error: Status 1 encountered during processing.
To report a bug, see <http://guide.macports.org/#project.tickets>

[neverpanic (Clemens Lang)]

Please use WikiFormatting and remember to Cc the maintainer.

This is a known problem with Python baking the compiler used to compile it into the binary and using it to compile any python modules. You can fix this by either (1) rebuilding all your ports (the only way to be sure), or (2) by rebuilding your python: sudo port -n upgrade --force python27, sudo port clean mercurial and try again.

While you're at it, you might want to rebuild your perl installation, if you happen to have any, the same way.