NoMethodError: undefined method `to_sym' for [:job, [{:name=>"build_branch"}]]:Array

https://sentry.gitlab.net/gitlab/gitlabcom/issues/1041712/

NoMethodError: undefined method `to_sym' for [:job, [{:name=>"build_branch"}]]:Array
Did you mean?  to_s
               to_set
  gitlab/ci/config/normalizer.rb:35:in `block in expand_names'
    parallelized_jobs[job_name.to_sym] || job_name
  gitlab/ci/config/normalizer.rb:34:in `each'
    job_names.flat_map do |job_name|
  gitlab/ci/config/normalizer.rb:34:in `flat_map'
    job_names.flat_map do |job_name|
  gitlab/ci/config/normalizer.rb:34:in `expand_names'
    job_names.flat_map do |job_name|
  gitlab/ci/config/normalizer.rb:22:in `block in normalize_jobs'
    config[:needs] = expand_names(config[:needs])
...
(131 additional frame(s) were not displayed)

NoMethodError: undefined method `to_sym' for [:job, [{:name=>"build_branch"}]]:Array
Did you mean?  to_s
               to_set