NoMethodError: undefined method `any?' for nil:NilClass

https://sentry.gitlab.net/gitlab/gitlabcom/issues/809723/

NoMethodError: undefined method `any?' for nil:NilClass
  gitlab/ci/ansi2html.rb:311:in `open_new_tag'
    if @sections.any?
  gitlab/ci/ansi2html.rb:288:in `ensure_open_new_tag'
    open_new_tag if @n_open_tags == 0
  gitlab/ci/ansi2html.rb:278:in `write_in_tag'
    ensure_open_new_tag
  gitlab/ci/ansi2html.rb:172:in `block in convert'
    write_in_tag s.scan(/./m)
  gitlab/ci/ansi2html.rb:156:in `each_line'
    stream.each_line do |line|
...
(127 additional frame(s) were not displayed)

NoMethodError: undefined method `any?' for nil:NilClass