NoMethodError: undefined method `fire_state_event' for nil:NilClass

https://sentry.gitlab.net/gitlab/gitlabcom/issues/562765/

NoMethodError: undefined method `fire_state_event' for nil:NilClass
  build_success_worker.rb:34:in `stop_environment'
    build.persisted_environment.fire_state_event(:stop)
  build_success_worker.rb:13:in `block in perform'
    stop_environment(build) if build.stops_environment?
  active_support/core_ext/object/try.rb:74:in `try!'
    yield self
  active_support/core_ext/object/try.rb:63:in `try'
    try!(*a, &b) if a.empty? || respond_to?(a.first)
  build_success_worker.rb:11:in `perform'
    Ci::Build.find_by(id: build_id).try do |build|
...
(38 additional frame(s) were not displayed)

undefined method `fire_state_event' for nil:NilClass