Patched _rake definition for zsh

_rake.zsh

#compdef rake

# rake, version 0.8.3

local curcontext="$curcontext" state line expl ret=1
typeset -A opt_args

_arguments -C -s -S \
  '(--classic-namespace -C)'{--classic-namespace,-C}'[put Task and FileTask in the top level namespace]' \
  '(--dry-run -n)'{--dry-run,-n}'[do a dry run without executing actions]' \
  '(- *)'{--describe,-D}'[describe the tasks (matching the specified pattern), then exit]:pattern::' \
  '(--execute -e)'{--execute,-e}'[execute some Ruby code and exit]:Ruby code:' \
  '(--execute-print -p)'{--execute-print,-p}'[execute some Ruby code, print the result, then exit]:Ruby code:' \
  '(--execute-continue -E)'{--execute-continue,-E}'[execute some Ruby code, then continue with normal task processing]:Ruby code:' \
  '(- *)'{--help,-h,-H}'[display help information]' \
  \*{--libdir,-I}'[include specified directory in the search path for required modules]:library directory:_files -/' \
  '(--rakelibdir --rakelib -R)'{--rakelibdir,--rakelib,-R}'[auto-import any .rake files in the specified directory. (default is 'rakelib')]:rake library directory:_files -/' \
  '(--nosearch -N)'{--nosearch,-N}'[do not search parent directories for the Rakefile]' \
  '(- *)'{--prereqs,-P}'[display the tasks and prerequisites, then exit]' \
  '(--quiet -q --silent -s --verbose -v)'{--quiet,-q}'[do not log messages to standard output]' \
  '(--rakefile -f)'{--rakefile,-f}'[use specified file as the rakefile]:rake file:_files' \
  \*{--require,-r}'[require specified module before executing rakefile]:library:->library' \
  '(- *)--rules[trace the rules resolution]' \
  '(--quiet -q --silent -s --verbose -v)'{--silent,-s}"[like --quiet, but also suppresses the 'in directory' announcement]" \
  '(--system,-g)'{--system,-g}'[using system wide (global) rakefiles (usually '~/.rake/*.rake')]' \
  '(- *)'{--tasks,-T}'[display the tasks (matching the specified pattern) with descriptions, then exit]:pattern::' \
  '(--trace -t)'{--trace,-t}'[turn on invoke/execute tracing, enable full backtrace]' \
  '(--quiet -q --silent -s --verbose -v)'{--verbose,-v}'[log message to standard output (default)]' \
  '(- *)'{--version,-V}'[display version information]' \
  '*:target:->target' && ret=0

case "$state" in
  library)
    local -a dirs
    dirs=( $(_call_program directories ruby -e 'puts\ \$:' 2>/dev/null) ${(s.:.)opt_args[-I]} )
    _wanted libraries expl library _path_files -W dirs && ret=0
  ;;
  target)
    local -a targets
    targets=( ${${(f)"$(_call_program targets $words[1] -sT $opt_args[(I)(-N|--nosearch)] ${(kv)opt_args[(I)(-f|--rakefile)]} 2>/dev/null)"}/(#b)rake ([^ ]##) ##\# (*)/${${match[1]}//:/\\:}:${match[2]:l}} )
    if (( ! ${targets[(I)rake aborted!]} )) then
      _describe -t targets 'rake target' targets && ret=0
    else
      _message -e targets 'rake target'
    fi
  ;;
esac

if [[ $PREFIX == *'='* ]]
then
  # Complete make variable as if shell variable
  compstate[parameter]="${PREFIX%%\=*}"
  compset -P 1 '*='
  _value "$@" && ret=0
fi

return ret

Lines 49 to 55 added, lifted from _make