Check for nil PATH
Check for nil PATH

fixes #2006

pivotal-cf-experimental/bundler,tgxworld/bundler,jasonkarns/bundler,RochesterinNYC/bundler,mattbrictson/bundler-1,nju520/bundler,EasonYi/bundler,patvice/bundler,carpodaster/bundler,dilumnavanjana/bundler,philnash/bundler,Teino1978-Corp/Teino1978-Corp-bundler,roseweixel/bundler,joshsoftware/bundler,asymmetric/bundler,christer155/bundler,jaym/bundler,roseweixel/bundler,EasonYi/bundler,EthanK28/bundler,chulkilee/bundler,rkh/bundler,ipmobiletech/bundler,mdorrance/bundler,frsyuki/bundler,masarakki/bundler,neslom/bundler,steved/bundler,mpapis/bundler,seanlinsley/bundler,Eric-Guo/bundler,suhastech/bundler,AiyionPrime/bundler,h4ck3rm1k3/bundler,Eric-Guo/bundler,e2/bundler,Wirachmat/bundler,jingweno/bundler,smlance/bundler,Teino1978-Corp/Teino1978-Corp-bundler,TimMoore/bundler,ligi/bundler,nju520/bundler,wenderjean/bundler,anil826/bundler,pivotal-cf-experimental/bundler,PG-kura/bundler,pjump/bundler,simplybusiness/bundler,chulkilee/bundler,pjump/bundler,suhastech/bundler,robinboening/bundler,jingweno/bundler,TimMoore/bundler,chef/bundler,robinboening/bundler,bronzdoc/bundler,vemmaverve/bundler,haonaturel/bundler,seanlinsley/bundler,schaary/bundler,AiyionPrime/bundler,byroot/bundler,agis-/bundler,elovelan/bundler,ngpestelos/bundler,ipmobiletech/bundler,CorainChicago/bundler,eagletmt/bundler,frsyuki/bundler,cstrahan/bundler,philnash/bundler,haocafes/bundler,jasonkarns/bundler,sideci-sample/sideci-sample-bundler,kohgpat/bundler,asutoshpalai/bundler,danimashu/bundler,gregkare/bundler,mpapis/bundler,PG-kura/bundler,bundler/bundler,h4ck3rm1k3/bundler,Elffers/bundler,1337807/bundler,lmtim/bundler,agis-/bundler,ximus/bundler,asutoshpalai/bundler,schaary/bundler,steved/bundler,bundler/bundler,byroot/bundler,jaym/bundler,mdorrance/bundler,simplybusiness/bundler,bronzdoc/bundler,r7kamura/bundler,haonature888/bundler,asymmetric/bundler,dilumnavanjana/bundler,gregkare/bundler,elovelan/bundler,christer155/bundler,gentoo/bundler,davydovanton/bundler,wenderjean/bundler,masarakki/bundler,zhangkuaiji/bundler,tgxworld/bundler,cdwort/bundler,davydovanton/bundler,cdwort/bundler,CorainChicago/bundler,joshsoftware/bundler,ligi/bundler,ngpestelos/bundler,mvz/bundler,twcctz500000/bundler,smlance/bundler,anil826/bundler,mvz/bundler,sideci-sample/sideci-sample-bundler,Elffers/bundler,zhangkuaiji/bundler,chef/bundler,EthanK28/bundler,Wirachmat/bundler,RochesterinNYC/bundler,danimashu/bundler,lmtim/bundler,cstrahan/bundler,haonature/bundler,carpodaster/bundler,neslom/bundler,ximus/bundler,kohgpat/bundler,mattbrictson/bundler-1,JuanitoFatas/bundler,patvice/bundler