Error: invalid attribute: version

brew --config

$ brew --config
HOMEBREW_VERSION: 0.9.5
ORIGIN: https://github.com/Homebrew/homebrew
HEAD: b12444ba6e1ac1d596a70ff4c777d9386d0791ac
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
CPU: quad-core 64-bit sandybridge
OS X: 10.9.2-x86_64
Xcode: 5.1.1
CLT: 5.1.0.0.1.1396320587
Clang: 5.1 build 503
X11: 2.7.5 => /opt/X11
System Ruby: 1.8.7-358
Perl: /usr/bin/perl
Python: /usr/local/bin/python => /usr/local/Cellar/python/2.7.6_1/Frameworks/Python.framework/Versions/2.7/bin/python2.7
Ruby: /usr/bin/ruby

brew doctor

$ brew doctor
Error: invalid attribute: version
Please report this bug:
    https://github.com/Homebrew/homebrew/wiki/troubleshooting
/usr/local/Library/Homebrew/formula.rb:71:in `validate_attributes'
/usr/local/Library/Homebrew/formula.rb:69:in `each'
/usr/local/Library/Homebrew/formula.rb:69:in `validate_attributes'
/usr/local/Library/Homebrew/formula.rb:41:in `initialize'
/usr/local/Library/Homebrew/formulary.rb:48:in `new'
/usr/local/Library/Homebrew/formulary.rb:48:in `get_formula'
/usr/local/Library/Homebrew/formulary.rb:190:in `factory'
/usr/local/Library/Homebrew/formula.rb:377:in `installed'
/usr/local/Library/Homebrew/formula.rb:375:in `map'
/usr/local/Library/Homebrew/formula.rb:375:in `installed'
/usr/local/Library/Homebrew/cmd/doctor.rb:895:in `check_missing_deps'
/usr/local/Library/Homebrew/cmd/doctor.rb:1132:in `send'
/usr/local/Library/Homebrew/cmd/doctor.rb:1132:in `doctor'
/usr/local/Library/Homebrew/cmd/doctor.rb:1131:in `each'
/usr/local/Library/Homebrew/cmd/doctor.rb:1131:in `doctor'
/usr/local/Library/brew.rb:105:in `send'
/usr/local/Library/brew.rb:105

brew outdated

$ brew outdated
Error: invalid attribute: version
Please report this bug:
    https://github.com/Homebrew/homebrew/wiki/troubleshooting
/usr/local/Library/Homebrew/formula.rb:71:in `validate_attributes'
/usr/local/Library/Homebrew/formula.rb:69:in `each'
/usr/local/Library/Homebrew/formula.rb:69:in `validate_attributes'
/usr/local/Library/Homebrew/formula.rb:41:in `initialize'
/usr/local/Library/Homebrew/formulary.rb:48:in `new'
/usr/local/Library/Homebrew/formulary.rb:48:in `get_formula'
/usr/local/Library/Homebrew/formulary.rb:190:in `factory'
/usr/local/Library/Homebrew/formula.rb:377:in `installed'
/usr/local/Library/Homebrew/formula.rb:375:in `map'
/usr/local/Library/Homebrew/formula.rb:375:in `installed'
/usr/local/Library/Homebrew/cmd/outdated.rb:16:in `outdated_brews'
/usr/local/Library/Homebrew/cmd/outdated.rb:6:in `outdated'
/usr/local/Library/brew.rb:105:in `send'
/usr/local/Library/brew.rb:105