ruby 1.9 also has rake in stdlib
ruby 1.9 also has rake in stdlib

dlorson/gentle-buildpack,hatofmonkeys/ruby-testing-buildpack,wakermahmud/heroku-buildpack-jekyll,cloudn/buildpack-ruby,ablease/custom-buildpack,zoomer/heroku-buildpack-ruby-bower,ericroberts/heroku-buildpack-ruby,ekaranto/rails4-bluemix-buildpack,blueapron/heroku-buildpack-ruby,cloudfoundry/ruby-buildpack,space150/heroku-buildpack-ruby,donnykurnia/heroku-buildpack-ruby,CPPWind/ruby-buildpack,rvizza/heroku-buildpack-gsl-ruby,stefansundin/heroku-buildpack-ruby,space150/heroku-buildpack-ruby,cloudn/buildpack-ruby,ekaranto/rails4-bluemix-buildpack,gbenedict/heroku-buildpack-ruby,fcruxen/ruby-buildpack,dlorson/gentle-buildpack,icelab/heroku-buildpack-ruby,sstelfox/buildpack-ruby,swipesense/heroku-buildpack-ruby,jumptvs/BP_Ruby,righi/instacart-heroku-buildpack,zunda/heroku-buildpack-ruby,bskyb-commerce/ruby-buildpack,takii/db2rubybuildpack,mattmanning/heroku-buildpack-ruby-jekyll,electricobjects/heroku-buildpack-ruby,jumptvs/BP_Ruby,instacart/heroku-buildpack-ruby,musicglue/heroku-buildpack-ruby,sky-uk/ruby-buildpack,shuber/heroku-buildpack-ruby,instacart/heroku-buildpack-ruby,DyegoCosta/heroku-buildpack-ruby,DigitalInnovation/heroku-buildpack-mslabs,dtao/teeny-buildpack,sky-uk/ruby-buildpack,Jonty/ruby-buildpack,reesio/heroku-buildpack-ruby,tpope/heroku-buildpack-ruby-tpope,takii/db2rubybuildpack,scottatron/moc-buildpack,michaelphines/alexa-nest,schu/heroku-buildpack-ruby,simonnordberg/heroku-buildpack-ruby,rowanoulton/heroku-buildpack-ruby,fcruxen/ruby-buildpack,daltonrenaldo/heroku-buildpack-ruby,diasks2/heroku-buildpack-mecab,Altoros/ruby-buildpack,barakav/heroku-buildpack-ruby,KoanHealth/heroku-buildpack-marvin-setup,hellojustin/heroku-buildpack-custom-ruby,zoomer/heroku-buildpack-ruby-bower,takii/heroku-buildpack-ruby,sky-uk/ruby-buildpack,crdschurch/heroku-buildpack-ruby,erintherad/heroku-buildpack-ruby,hellojustin/heroku-buildpack-custom-ruby,wakermahmud/heroku-buildpack-jekyll,brightbytes/heroku-buildpack-ruby-without-assets-precompile,jgable/buildpack-ruby-rack-setup-tasks,guidance-guarantee-programme/heroku-buildpack-princexml-old,sky-uk/ruby-buildpack,fgbreel/heroku-buildpack-ruby,cloudControl/buildpack-ruby,cloudControl/buildpack-ruby,samfrench/heroku-buildpack-ruby,icelab/heroku-buildpack-ruby,donnykurnia/heroku-buildpack-ruby,ilpoldo/heroku-buildpack-ruby,tdenovan/heroku-buildpack-ruby,jayshreeanand/heroku-buildpack-ruby,derrek/heroku-buildpack-ruby,cmaggard/heroku-buildpack-turbo-sprockets,orenyk/heroku-buildpack-ruby,pilotcreative/heroku-buildpack-ruby,lyoshenka/heroku-buildpack-ruby-jekyll,takii/heroku-buildpack-ruby,packetmonkey/heroku-buildpack-ruby,stolt45/heroku-buildpack-ruby-with-sqlite3,leonardykris/mos-ruby-buildpack,engineyard/heroku-buildpack-ruby,pkgr/heroku-buildpack-ruby,Nedomas/heroku-buildpack-ruby-minus-node-with-node-paths,rvizza/heroku-buildpack-gsl-ruby,anay/buildpack-ruby-with-oracle-jdk,jasonlevens/heroku-buildpack-ruby,takii/db2rubybuildpack,tdenovan/heroku-buildpack-ruby,jonasoberschweiber/heroku-buildpack-ruby,mattwalters/heroku-buildpack-ruby,Dim25/heroku-buildpack-ruby-GSL,jonseaberg/heroku-buildpack-turbo-sprockets,Nedomas/heroku-buildpack-ruby-minus-node-with-node-paths,engineyard/heroku-buildpack-ruby,teodor-pripoae/heroku-buildpack-ruby,reesio/heroku-buildpack-ruby,heroku/heroku-buildpack-ruby,bskyb-commerce/help-heroku-buildpack,mintybit/heroku-buildpack-ruby,ablease/custom-buildpack,mintybit/heroku-buildpack-ruby,ibmdb/db2rubybuildpack,andycroll/heroku-buildpack-jekyll,trumaker/heroku-buildpack-turbo-sprockets,KoanHealth/heroku-buildpack-marvin-setup,pietrop/heroku-buildpack-ruby,cloudfoundry/ruby-buildpack,bellycard/heroku-buildpack-ruby,d-reinhold/cf-buildpack-ruby,bskyb-commerce/ruby-buildpack,qnyp/heroku-buildpack-ruby-bower,cloudn/buildpack-ruby,gls1/heroku-buildpack-ruby-pdftk,qstream/heroku-buildpack-ruby,codykrieger/heroku-buildpack-jekyll,CPPWind/ruby-buildpack,jonseaberg/heroku-buildpack-turbo-sprockets,fcruxen/ruby-buildpack,mattmanning/heroku-buildpack-ruby-jekyll,dieze/heroku-buildpack-ruby-hooks,ablease/custom-buildpack,fgbreel/heroku-buildpack-ruby,Micka33/heroku-buildpack-ruby-liblua,packetmonkey/heroku-buildpack-ruby,stolt45/heroku-buildpack-ruby-with-sqlite3,catalyzeio/buildpack-ruby,tenjikinc/heroku-buildpack-ruby,simonnordberg/heroku-buildpack-ruby,lyoshenka/heroku-buildpack-ruby-jekyll,ablease/custom-buildpack,teodor-pripoae/heroku-buildpack-ruby,jayshreeanand/heroku-buildpack-ruby,redhotvengeance/heroku-buildpack-deep-thought,Genius/heroku-buildpack-ruby,vhx/heroku-buildpack,tomwolfe/heroku-buildpack-gsl-ruby,diasks2/heroku-buildpack-mecab,Git-Host/prelang-buildpack,mrhenry/heroku-buildpack-ruby,cmaggard/heroku-buildpack-turbo-sprockets,bwaite-jaroop/heroku-buildpack-ruby,Altoros/ruby-buildpack,schu/heroku-buildpack-ruby,ericboehs/heroku-buildpack-ruby,jasonlevens/heroku-buildpack-ruby,CPPWind/ruby-buildpack,awebneck/heroku-buildpack-canvas,fcruxen/ruby-buildpack,guidance-guarantee-programme/heroku-buildpack-princexml-old,ruby/heroku-buildpack-www-ruby-lang,markaschneider/heroku-buildpack-ruby-ffmpeg-sox,barakav/heroku-buildpack-ruby,bellycard/heroku-buildpack-ruby,moneyadviceservice/heroku-buildpack-ruby-bowndler,qstream/heroku-buildpack-ruby,DigitalInnovation/heroku-buildpack-mslabs,Scalingo/ruby-buildpack,sky-uk/help-heroku-buildpack,amaltson/heroku-buildpack-ruby,erintherad/heroku-buildpack-ruby,cloudfoundry/ruby-buildpack,dieze/heroku-buildpack-ruby-hooks,ibmdb/db2rubybuildpack,scottatron/moc-buildpack,dleavitt/heroku-buildpack-ruby,dtao/deft-buildpack-ruby,brightbytes/heroku-buildpack-ruby-without-assets-precompile,zidekmat/buildpack-ruby,beydogan/ruby-buildpack,blueapron/heroku-buildpack-ruby,hatofmonkeys/ruby-testing-buildpack,michaelphines/alexa-nest,catalyzeio/buildpack-ruby,iamjarvo/ruby-buildpack,CPPWind/ruby-buildpack,takii/db2rubybuildpack,leonardykris/mos-ruby-buildpack,HYPERHYPER/heroku-buildpack-ruby,shuber/heroku-buildpack-ruby,anay/buildpack-ruby-with-oracle-jdk,cordata/heroku-buildpack-ruby,pilotcreative/heroku-buildpack-ruby,DouglasAllen/heroku-buildpack-ruby,hpcloud/ruby-buildpack,Jonty/ruby-buildpack,stefansundin/heroku-buildpack-ruby,tpope/heroku-buildpack-ruby-tpope,ChefSteps/heroku-buildpack-ruby,ekaranto/rails4-bluemix-buildpack,andycroll/heroku-buildpack-jekyll,mrhenry/heroku-buildpack-ruby,sstelfox/buildpack-ruby,hixi/heroku-buildpack-ruby,samfrench/heroku-buildpack-ruby,hpcloud/ruby-buildpack,cloudfoundry/ruby-buildpack,mperejda/heroku-buildpack-ruby,cloudn/buildpack-ruby,qnyp/heroku-buildpack-ruby-bower,ndbroadbent/heroku-buildpack-turbo-sprockets,0x00evil/heroku-buildpack-ruby,electricobjects/heroku-buildpack-ruby,zunda/heroku-buildpack-ruby,hpcloud/ruby-buildpack,mattwalters/heroku-buildpack-ruby,gls1/heroku-buildpack-ruby-pdftk-new,schu/buildpack-testing,hpcloud/ruby-buildpack,bskyb-commerce/ruby-buildpack,derrek/heroku-buildpack-ruby,Jonty/ruby-buildpack,trumaker/heroku-buildpack-turbo-sprockets,ilpoldo/heroku-buildpack-ruby,recursecenter/heroku-buildpack-ruby,Altoros/ruby-buildpack,ericboehs/heroku-buildpack-ruby,heroku/heroku-buildpack-ruby,markaschneider/heroku-buildpack-ruby-ffmpeg-sox,bskyb-commerce/help-heroku-buildpack,cordata/heroku-buildpack-ruby,gls1/heroku-buildpack-ruby-pdftk,schu/buildpack-testing,hatofmonkeys/ruby-testing-buildpack,cloudfoundry/ruby-buildpack,iamjarvo/ruby-buildpack,rowanoulton/heroku-buildpack-ruby,gls1/heroku-buildpack-ruby-pdftk-new,moneyadviceservice/heroku-buildpack-ruby-bowndler,d-reinhold/cf-buildpack-ruby,dleavitt/heroku-buildpack-ruby,beydogan/ruby-buildpack,dtao/teeny-buildpack,ibmdb/db2rubybuildpack,aarongray/heroku-buildpack-ruby,codykrieger/heroku-buildpack-jekyll,ericroberts/heroku-buildpack-ruby,0x00evil/heroku-buildpack-ruby,righi/instacart-heroku-buildpack,ekaranto/rails4-bluemix-buildpack,HYPERHYPER/heroku-buildpack-ruby,Micka33/heroku-buildpack-ruby-liblua,DouglasAllen/heroku-buildpack-ruby,Git-Host/prelang-buildpack,jgable/buildpack-ruby-rack-setup-tasks,ChefSteps/heroku-buildpack-ruby,allomov/fat-free-heroku-buildpack-ruby,awebneck/heroku-buildpack-canvas,orlando/heroku-buildpack-ruby,sky-uk/help-heroku-buildpack,jumptvs/BP_Ruby,ltrademark/heroku-buildpack-ruby,pkgr/heroku-buildpack-ruby,ndbroadbent/heroku-buildpack-turbo-sprockets,ascot21/heroku-buildpack-turbo-sprockets,iamjarvo/ruby-buildpack,redhotvengeance/heroku-buildpack-deep-thought,bwaite-jaroop/heroku-buildpack-ruby,gbenedict/heroku-buildpack-ruby,orlando/heroku-buildpack-ruby,vhx/heroku-buildpack,Altoros/ruby-buildpack,d-reinhold/cf-buildpack-ruby,zidekmat/buildpack-ruby,Genius/heroku-buildpack-ruby,Scalingo/ruby-buildpack,pietrop/heroku-buildpack-ruby,Jonty/ruby-buildpack,ascot21/heroku-buildpack-turbo-sprockets,hixi/heroku-buildpack-ruby,Dim25/heroku-buildpack-ruby-GSL,tomwolfe/heroku-buildpack-gsl-ruby,makifund/heroku-buildpack-ruby,DyegoCosta/heroku-buildpack-ruby,jumptvs/BP_Ruby,recursecenter/heroku-buildpack-ruby,iamjarvo/ruby-buildpack,amaltson/heroku-buildpack-ruby,dtao/deft-buildpack-ruby,ltrademark/heroku-buildpack-ruby,bskyb-commerce/ruby-buildpack,jonasoberschweiber/heroku-buildpack-ruby,daltonrenaldo/heroku-buildpack-ruby,aarongray/heroku-buildpack-ruby,tenjikinc/heroku-buildpack-ruby,orenyk/heroku-buildpack-ruby,mperejda/heroku-buildpack-ruby,allomov/fat-free-heroku-buildpack-ruby,swipesense/heroku-buildpack-ruby,crdschurch/heroku-buildpack-ruby,makifund/heroku-buildpack-ruby,musicglue/heroku-buildpack-ruby