Brew failure to install tmux

brew-log-tmux-install

➜  ~  brew install -v tmux
==> Downloading http://sourceforge.net/projects/tmux/files/tmux/tmux-1.5/tmux-1.5.tar.gz
File already downloaded in /Users/cgarvis/Library/Caches/Homebrew
/usr/bin/tar xf /Users/cgarvis/Library/Caches/Homebrew/tmux-1.5.tar.gz
==> ./configure --disable-dependency-tracking --prefix=/usr/local/Cellar/tmux/1.5 --sysconfdir=/usr/local/etc
./configure --disable-dependency-tracking --prefix=/usr/local/Cellar/tmux/1.5 --sysconfdir=/usr/local/etc
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... etc/install-sh -c -d
checking for gawk... no
checking for mawk... no
checking for nawk... no
checking for awk... awk
checking whether make sets $(MAKE)... yes
checking build system type... x86_64-apple-darwin11.2.0
checking host system type... x86_64-apple-darwin11.2.0
checking for gcc... /usr/bin/llvm-gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables... 
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether /usr/bin/llvm-gcc accepts -g... yes
checking for /usr/bin/llvm-gcc option to accept ISO C89... none needed
checking for style of include used by make... GNU
checking dependency style of /usr/bin/llvm-gcc... none
checking whether /usr/bin/llvm-gcc and cc understand -c and -o together... yes
checking how to run the C preprocessor... /usr/bin/llvm-gcc -E
checking for grep that handles long lines and -e... /usr/bin/grep
checking for egrep... /usr/bin/grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking bitstring.h usability... yes
checking bitstring.h presence... yes
checking for bitstring.h... yes
checking curses.h usability... yes
checking curses.h presence... yes
checking for curses.h... yes
checking dirent.h usability... yes
checking dirent.h presence... yes
checking for dirent.h... yes
checking fcntl.h usability... yes
checking fcntl.h presence... yes
checking for fcntl.h... yes
checking for inttypes.h... (cached) yes
checking libutil.h usability... no
checking libutil.h presence... no
checking for libutil.h... no
checking ncurses.h usability... yes
checking ncurses.h presence... yes
checking for ncurses.h... yes
checking ndir.h usability... no
checking ndir.h presence... no
checking for ndir.h... no
checking paths.h usability... yes
checking paths.h presence... yes
checking for paths.h... yes
checking pty.h usability... no
checking pty.h presence... no
checking for pty.h... no
checking for stdint.h... (cached) yes
checking sys/dir.h usability... yes
checking sys/dir.h presence... yes
checking for sys/dir.h... yes
checking sys/ndir.h usability... no
checking sys/ndir.h presence... no
checking for sys/ndir.h... no
checking sys/tree.h usability... no
checking sys/tree.h presence... no
checking for sys/tree.h... no
checking term.h usability... yes
checking term.h presence... yes
checking for term.h... yes
checking util.h usability... yes
checking util.h presence... yes
checking for util.h... yes
checking for gcc that whines about -I... yes
checking for glibc... no
checking for clock_gettime in -lrt... no
checking for library containing event_init... no
configure: error: "libevent not found"
==> Exit Status: 1
http://github.com/mxcl/homebrew/blob/master/Library/Formula/tmux.rb#L12
==> Environment
HOMEBREW_VERSION: 0.8.1
HEAD: 35deeadfd998fe598cec077d96b5da0fb40105e1
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
Hardware: 8-core 64-bit sandybridge
OS X: 10.7.2
Kernel Architecture: x86_64
Ruby: 1.8.7-249
/usr/bin/ruby => /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
Xcode: 4.2
GCC-4.0: N/A
GCC-4.2: N/A
LLVM: build 2336
Clang: 3.0 build 211
MacPorts or Fink? false
X11 installed? true
==> Build Flags
CC: /usr/bin/llvm-gcc => /usr/llvm-gcc-4.2/bin/llvm-gcc-4.2
CXX: /usr/bin/llvm-g++ => /usr/llvm-gcc-4.2/bin/llvm-g++-4.2
LD: /usr/bin/llvm-gcc => /usr/llvm-gcc-4.2/bin/llvm-gcc-4.2
CFLAGS: -O3 -w -pipe  -march=core2 -msse4
CXXFLAGS: -O3 -w -pipe  -march=core2 -msse4
LDFLAGS: -lresolv
MAKEFLAGS: -j8