NoMethodError: undefined method `data' for nil:NilClass

https://sentry.gitlab.net/gitlab/gitlabcom/issues/4121245/?referrer=gitlab_plugin

NoMethodError: undefined method `data' for nil:NilClass
  app/services/projects/blame_service.rb:98:in `blob_lines_count'
    @blob_lines_count ||= blob.data.lines.count
  app/services/projects/blame_service.rb:39:in `total_pages'
    total = (blob_lines_count.to_f / per_page).ceil
  app/services/projects/blame_service.rb:94:in `overlimit?'
    page > total_pages
  app/services/projects/blame_service.rb:76:in `extract_page'
    return 1 if page < 1 || overlimit?(page)
  app/services/projects/blame_service.rb:16:in `initialize'
    @page = extract_page(params)
...
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