sudo port -vd selftupdate error

gistfile1.txt

checking build system type... i386-apple-darwin11.0.0
checking host system type... i386-apple-darwin11.0.0
checking target system type... i386-apple-darwin11.0.0
checking MacPorts version... 2.0.0
checking for sw_vers... /usr/bin/sw_vers
checking for defaults... /usr/bin/defaults
checking for xcode-select... no
checking Mac OS X version... 10.7
checking Xcode version... 3.2.3
checking for gcc... /usr/bin/llvm-gcc-4.2
checking whether the C compiler works... no
configure: error: in `/opt/local/var/macports/sources/rsync.macports.org/release/base':
configure: error: C compiler cannot create executables
See `config.log' for more details
shell command "cd /opt/local/var/macports/sources/rsync.macports.org/release/base && CC=/usr/bin/llvm-gcc-4.2 ./configure --prefix=/opt/local --with-tclpackage=/Library/Tcl --with-install-user=root --with-install-group=admin --with-directory-mode=0755 --enable-readline && make && make install" returned error 77
DEBUG: Error installing new MacPorts base: shell command failed (see log for details)
    while executing
"macports::selfupdate [array get global_options] base_updated"
Error: /opt/local/bin/port: port selfupdate failed: Error installing new MacPorts base: shell command failed (see log for details)