https://sentry.gitlab.net/gitlab/gitlabcom/issues/739466/ ``` NoMethodError: undefined method `index' for nil:NilClass gitlab/diff/file.rb:103:in `diff_hunk' diff_line_index = diff_line.index diff_note.rb:39:in `create_diff_file' .merge(diff: diff_file.diff_hunk(diff_line)) gitlab/metrics/instrumentation.rb:161:in `block in create_diff_file' .measure { super } gitlab/metrics/method_call.rb:36:in `measure' retval = yield gitlab/metrics/instrumentation.rb:161:in `create_diff_file' .measure { super } ... (48 additional frame(s) were not displayed) undefined method `index' for nil:NilClass ```