brew update
error: The following untracked working tree files would be overwritten by checkout:
	.gitignore
	Library/Aliases/0mq
	Library/Aliases/Secret Rabbit Code
	Library/Aliases/alut
	Library/Aliases/android
	Library/Aliases/apache-activemq
	Library/Aliases/apache-fop
	Library/Aliases/aws-as
	Library/Aliases/aws-mon
	Library/Aliases/beanstalkd
	Library/Aliases/bjam
	Library/Aliases/bzr
	Library/Aliases/cowthink
	Library/Aliases/cpanm
	Library/Aliases/ctags-exuberant
	Library/Aliases/db
	Library/Aliases/dbus
	Library/Aliases/dejagnu
	Library/Aliases/eyeD3
	Library/Aliases/firefly
	Library/Aliases/fluidsynth
	Library/Aliases/fsa
	Library/Aliases/gearmand
	Library/Aliases/gnu-scientific-library
	Library/Aliases/google-go
	Library/Aliases/gs
	Library/Aliases/gtk
	Library/Aliases/gtypist
	Library/Aliases/hudson
	Library/Aliases/hugs
	Library/Aliases/ipsum
	Library/Aliases/jocr
	Library/Aliases/jslint
	Library/Aliases/lcms
	Library/Aliases/leg
	Library/Aliases/libcryptopp
	Library/Aliases/libgd
	Library/Aliases/libgeoip
	Library/Aliases/libjpeg
	Library/Aliases/libjpg
	Library/Aliases/liblabjackusb
	Library/Aliases/libmad
	Library/Aliases/libmcrypt
	Library/Aliases/liboggz
	Library/Aliases/libqrencode
	Library/Aliases/libtag
	Library/Aliases/libtasn
	Library/Aliases/mc
	Library/Aliases/mongo
	Library/Aliases/mp4box
	Library/Aliases/node.js
	Library/Aliases/nsis
	Library/Aliases/o-caml
	Library/Aliases/ocaml
	Library/Aliases/offlineimap
	Library/Aliases/omake
	Library/Aliases/ooc
	Library/Aliases/openocd
	Library/Aliases/p4
	Library/Aliases/p4d
	Library/Aliases/pipeviewer
	Library/Aliases/pkgconfig
	Library/Aliases/postgres
	Library/Aliases/rbx
	Library/Aliases/ree
	Library/Aliases/saga
	Library/Aliases/shell-fm
	Library/Aliases/slang
	Library/Aliases/stax-sdk
	Library/Aliases/style
	Library/Aliases/svn
	Library/Aliases/ultima4
	Library/Aliases/ultima7
	Library/Aliases/umfpack
	Library/Aliases/urxvt
	Library/Aliases/usb-multiplex-daemon
	Library/Aliases/zmq
	Library/Contributions/brew_bash_completion.sh
	Library/Contributions/brew_fish_completion.fish
	Library/Contributions/brew_zsh_completion.zsh
	Library/Contributions/examples/brew-bottle.rb
	Library/Contributions/examples/brew-depstree.rb
	Library/Contributions/examples/brew-dirty.rb
	Library/Contributions/examples/brew-graph
	Library/Contributions/examples/brew-grep
	Library/Contributions/examples/brew-leaves.rb
	Library/Contributions/examples/brew-linkapps.rb
	Library/Contributions/examples/brew-man
	Library/Contributions/examples/brew-missing.rb
	Library/Contributions/examples/brew-pull.rb
	Library/Contributions/examples/brew-readall.rb
	Library/Contributions/examples/brew-server
	Library/Contributions/examples/brew-switch.rb
	Library/Contributions/examples/brew-unpack.rb
	Library/Contributions/examples/brew-upgrade.rb
	Library/Contributions/examples/brew-which.rb
	Library/Contributions/manpages/brew-man.1.md
	Library/Contributions/manpages/brew.1.md
	Library/Formula/a2ps.rb
	Library/Formula/a52dec.rb
	Library/Formula/aacgain.rb
	Library/Formula/aalib.rb
	Library/Formula/aamath.rb
	Library/Formula/aardvark_shell_utils.rb
	Library/Formula/abcde.rb
	Library/Formula/abfind.rb
	Library/Formula/abiword.rb
	Library/Formula/abnfgen.rb
	Library/Formula/abook.rb
	Library/Formula/abuse.rb
	Library/Formula/ace.rb
	Library/Formula/ack.rb
	Library/Formula/activemq.rb
	Library/Formula/adamem.rb
	Library/Formula/adns.rb
	Library/Formula/adobe-air-sdk.rb
	Library/Formula/adplug.rb
	Library/Formula/advancecomp.rb
	Library/Formula/aescrypt.rb
	Library/Formula/afflib.rb
	Library/Formula/afsctool.rb
	Library/Formula/aften.rb
	Library/Formula/aget.rb
	Library/Formula/aggregate.rb
	Library/Formula/agrep.rb
	Library/Formula/aircrack-ng.rb
	Library/Formula/akonadi.rb
	Library/Formula/aldo.rb
	Library/Formula/algol68g.rb
	Library/Formula/alpine.rb
	Library/Formula/android-ndk.rb
	Library/Formula/android-sdk.rb
	Library/Formula/angband.rb
	Library/Formula/ansifilter.rb
	Library/Formula/antiword.rb
	Library/Formula/antlr.rb
	Library/Formula/aoeui.rb
	Library/Formula/apachetop.rb
	Library/Formula/apc.rb
	Library/
Aborting
Error: Failure while executing: git checkout -q master