brew install -v beanstalkd

gistfile1.txt

==> Downloading http://xph.us/dist/beanstalkd/beanstalkd-1.4.6.tar.gz
File already downloaded in /Users/dylan/Library/Caches/Homebrew
/usr/bin/tar xf /Users/dylan/Library/Caches/Homebrew/beanstalk-1.4.6.tar.gz
==> ./configure --disable-debug --disable-dependency-tracking --prefix=/usr/local/Cellar/beanstalk/1.4.6 --with-event=/usr/local
./configure --disable-debug --disable-dependency-tracking --prefix=/usr/local/Cellar/beanstalk/1.4.6 --with-event=/usr/local
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... ./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 whether to enable maintainer-specific portions of Makefiles... no
checking for style of include used by make... GNU
checking for gcc... /usr/bin/cc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether /usr/bin/cc accepts -g... yes
checking for /usr/bin/cc option to accept ISO C89... none needed
checking dependency style of /usr/bin/cc... none
checking for supported compiler flags...  -Wall -Werror
checking for gcc... (cached) /usr/bin/cc
checking whether we are using the GNU C compiler... (cached) yes
checking whether /usr/bin/cc accepts -g... (cached) yes
checking for /usr/bin/cc option to accept ISO C89... (cached) none needed
checking dependency style of /usr/bin/cc... (cached) none
checking if compiler supports -R... no
checking if compiler supports -Wl,-rpath,... yes
checking libevent install prefix... /usr/local
checking for posix_fallocate... no
checking for fdatasync... yes
checking for bind in -lsocket... no
checking for inet_aton in -lnsl... no
checking for event_get_version in -levent... yes
checking for event_reinit in -levent... yes
checking how to run the C preprocessor... /usr/bin/cc -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 for uint16_t... yes
configure: creating ./config.status
config.status: creating Makefile
config.status: creating config.h
config.status: executing depfiles commands
==> make install
make install 
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o beanstalkd.o beanstalkd.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o binlog.o binlog.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o conn.o conn.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o job.o job.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o ms.o ms.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o net.o net.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o port.o port.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o pq.o pq.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o primes.o primes.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o prot.o prot.c
/usr/bin/cc -DHAVE_CONFIG_H -I.     -O3 -march=core2 -msse4.1 -w -pipe  -Wall -Werror -I/usr/local/include -c -o tube.o tube.c
In file included from /usr/local/include/event2/event.h:48,
                 from /usr/local/include/event.h:192,
                 from conn.h:23,
                 from prot.h:22,
                 from tube.c:25:
/usr/include/stdio.h:446: error: expected identifier or ‘(’ before ‘void’
/usr/include/stdio.h:446: error: expected ‘)’ before numeric constant
make: *** [tube.o] Error 1
make: *** Waiting for unfinished jobs....
==> Exit Status: 2
http://github.com/mxcl/homebrew/blob/master/Library/Formula/beanstalk.rb#L14
==> Environment
HOMEBREW_VERSION: 0.8
HEAD: (none)
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
HOMEBREW_REPOSITORY: /usr/local
HOMEBREW_LIBRARY_PATH: /usr/local/Library/Homebrew
Hardware: dual-core 64-bit penryn
OS X: 10.7
Kernel Architecture: x86_64
Ruby: 1.8.7-249
/usr/bin/ruby => /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
Xcode: 4.1
GCC-4.0: N/A 
GCC-4.2: build 5666 
LLVM: build 2335 
MacPorts or Fink? false
X11 installed? true
==> Build Flags
CC: /usr/bin/cc => /usr/llvm-gcc-4.2/bin/llvm-gcc-4.2
CXX: /usr/bin/c++ => /usr/llvm-gcc-4.2/bin/llvm-g++-4.2
LD: /usr/bin/cc => /usr/llvm-gcc-4.2/bin/llvm-gcc-4.2
CFLAGS: -O3 -march=core2 -msse4.1 -w -pipe
CXXFLAGS: -O3 -march=core2 -msse4.1 -w -pipe
MAKEFLAGS: -j2

Error: Failed executing: make install 
Please report this bug: https://github.com/mxcl/homebrew/wiki/Checklist-before-filing-a-new-issue

Also try:
  `brew doctor` to check your setup for common problems.
  `brew missing` to check installed packages for missing deps.

FWIW, I've just run into exactly the same problem with macports, which suggests it's not a problem with either macports or homebrew.

Solved it!
This is caused by an upstream bug that's been fixed but not made it into homebrew or macports yet: beanstalkd/beanstalkd#49
There's an unreleased fix in MacPorts that will probably work in Homebrew too: http://trac.macports.org/ticket/31463

Yup, fixed already--Homebrew now patches Beanstalkd. See Homebrew/legacy-homebrew#6584 (comment)