rkt: output err on failure.
rkt: output err on failure.

Add the missing error for the message.

smarvin/rkt,rhvgoyal/rkt,MattDees/rkt,alban/rkt,iankronquist/rkt,monstermunchkin/rkt,nhlfr/rkt,ramitsurana/rkt,mike1729/rkt,ramitsurana/rkt,shobhit85/rkt,squaremo/rkt,mjg59/rkt,Wilybald/rkt,tmrts/rkt,sinfomicien/rkt,chrisseto/rkt,wparad/rkt,ChengTiesheng/rkt,clearlinux/rkt,ramitsurana/rkt,endocode/rkt,squaremo/rkt,akshaykarle/rkt,liugenping/rkt,sstabellini/rkt,linki/rkt,euank/rkt,cab105/rkt,MattDees/rkt,sgotti/rkt,akshaykarle/rkt,lucasallan/rkt,fdserr/rkt,sstabellini/rkt,matthaias/rkt,mattthias/pkg-rkt,Wilybald/rkt,rot26/rkt,euank/rkt,kbrwn/rkt,lsm5/rkt,matthaias/rkt,yifan-gu/rkt,yifan-gu/rkt,linki/rkt,crawford/rkt,kbrwn/rkt,s-urbaniak/rkt,mjg59/rkt,tv42/rkt,klizhentas/rkt,euank/rkt,joshix/rkt,bsmr-go/rkt,luebken/rkt,rkt/rkt,endocode/rkt,clearlinux/rkt,rhvgoyal/rkt,shtouff/rkt,shtouff/rkt,maquanyi/rkt,jasonchaffee/rkt,sinfomicien/rkt,Shashwatsh/rkt,ramitsurana05/rkt,iankronquist/rkt,dgonyeo/rkt,shobhit85/rkt,jjlakis/rkt,sgotti/rkt,michelangelo13/rkt,mattthias/pkg-rkt,Wilybald/rkt,s-urbaniak/rkt,klizhentas/rkt,iankronquist/rkt,jakon89/rkt,iaguis/rkt,monstermunchkin/rkt,nhlfr/rkt,intelsdi-x/rkt,Shashwatsh/rkt,intfrr/rkt,shobhit85/rkt,ChengTiesheng/rkt,s-urbaniak/rkt,intelsdi-x/rkt,achanda/rkt,jonboulle/rkt,rot26/rkt,smarvin/rkt,yifan-gu/rocket,intelsdi-x/rkt,mike1729/rkt,tv42/rkt,squeed/rkt,coreos/rkt,tmrts/rkt,ybubnov/rkt,rkt/rkt,krnowak/rkt,tixxdz/rkt,fdserr/rkt,kinvolk/rkt,coreos/rkt,achanda/rkt,intfrr/rkt,kinvolk/rkt,jakon89/rkt,MabinGo/rkt,luebken/rkt,linki/rkt,clearlinux/rkt,liugenping/rkt,blixtra/rkt,liubq919/rkt,cab105/rkt,shtouff/rkt,adfernandes/rkt,maquanyi/rkt,krnowak/rkt,jonboulle/rkt,robszumski/rocket,tixxdz/rkt,jjlakis/rkt,alexhersh/rkt,achanda/rkt,marineam/rkt,coreos/rkt,xnox/rkt,mike1729/rkt,mattthias/pkg-rkt,smarvin/rkt,squeed/rkt,wparad/rkt,matthaias/rkt,dalanlan/rkt,rkt/rkt,joshix/rkt,kinvolk/rkt,liubq919/rkt,ChengTiesheng/rkt,jjlakis/rkt,lee212/rkt,bsmr-go/rkt,il9ue/rkt,MabinGo/rkt,lsm5/rkt,jakon89/rkt,xnox/rkt,akshaykarle/rkt,lsm5/rkt,squeed/rkt,crawford/rkt,lee212/rkt,bsmr-go/rkt,klizhentas/rkt,liubq919/rkt,yifan-gu/rkt,sstabellini/rkt,ramitsurana05/rkt,il9ue/rkt,michelangelo13/rkt,tmrts/rkt,markllama/rkt,iaguis/rkt,cab105/rkt,lee212/rkt,blixtra/rkt,luebken/rkt,adfernandes/rkt,crawford/rkt,markllama/rkt,Yhgenomics/rkt,yifan-gu/rocket,jzelinskie/rkt,lucasallan/rkt,iaguis/rkt,robszumski/rocket,dgonyeo/rkt,mjg59/rkt,intfrr/rkt,sinfomicien/rkt,chrisseto/rkt,kinvolk/rkt,sgotti/rkt,MattDees/rkt,maquanyi/rkt,yifan-gu/rocket,ramitsurana05/rkt,ybubnov/rkt,jzelinskie/rkt,jonboulle/rkt,lucasallan/rkt,alban/rkt,alexhersh/rkt,lucasallan/rkt,marineam/rkt,marineam/rkt,alexhersh/rkt,MabinGo/rkt,michelangelo13/rkt,fdserr/rkt,nhlfr/rkt,squaremo/rkt,liugenping/rkt,blixtra/rkt,rkt/rkt,Wilybald/rkt,xnox/rkt,chrisseto/rkt,joshix/rkt,krnowak/rkt,jasonchaffee/rkt,endocode/rkt,monstermunchkin/rkt,Shashwatsh/rkt,il9ue/rkt,Yhgenomics/rkt,Yhgenomics/rkt,tixxdz/rkt,jasonchaffee/rkt,dalanlan/rkt,tv42/rkt,rot26/rkt,dalanlan/rkt,wparad/rkt,rhvgoyal/rkt,robszumski/rocket,kbrwn/rkt,jzelinskie/rkt,joshix/rkt,dgonyeo/rkt,ybubnov/rkt,markllama/rkt,alban/rkt,adfernandes/rkt