git - Unable to push to unqualified destination: master while deploying to demo branch -

i'm trying create demo branch application suppliers can login learn more does.

i have master branch deploys production on heroku. additionally, have staging branch deploys heroku staging environment. in github app created branch off of staging branch called 'demo'.

when deploy using circleci, receive following error:

unable push unqualified destination: master destination refspec neither matches existing ref on remote nor begins refs/, , unable guess prefix based on source ref.  git push git@heroku.com:foobar-demo.git $circle_sha1:master returned exit code 1  error: failed push refs 'git@heroku.com:foobar-demo.git' action failed: git push git@heroku.com:foobar-demo.git $circle_sha1:master 

my circle.yml looks following:

deployment:   staging:     branch: staging     commands:       - heroku maintenance:on --app foobar-staging       #- heroku scale worker=0 --app foobar-staging       - git push git@heroku.com:foobar-staging.git $circle_sha1:master       - heroku run rake db:migrate --app foobar-staging       #- heroku scale worker=x --app foobar-staging       - heroku maintenance:off --app foobar-staging    demo:     branch: demo     commands:       - heroku maintenance:on --app foobar-demo       #- heroku scale worker=0 --app foobar-demo       - git push git@heroku.com:lfoobar-demo.git $circle_sha1:master       - heroku run rake db:migrate --app foobar-demo       #- heroku scale worker=x --app foobar-demo       - heroku maintenance:off --app foobar-demo 

the deployment flow staging working fine, issue new demo branch. tried deleting branch , heroku app (foobar-demo.herokuapp.com) , haven't had luck.

i found solution in accepted answer in so thread.

i had change $circle_sha1:master $circle_sha1:refs/heads/master in circle.yml file.