ActionView::Template::Error (undefined method `title' for nil:NilClass)
Created by: rujews
giltab：7.14.3 url ：/gitlab/android/MyMoney/merge_requests
这个错误和merge request列表数据有关，有的会出现这个错误，有的不会。 我该怎么修复数据，进而修复这个问题？
the error log ：
ActionView::Template::Error (undefined method `title' for nil:NilClass):
42:
43: %span
44: %i.fa.fa-clock-o
45: = merge_request.milestone.title
46: - if merge_request.tasks?
47: %span.task-status
48: = merge_request.task_status
app/views/projects/merge_requests/_merge_request.html.haml:45:in `_app_views_projects_merge_requests__merge_request_html_haml___654517899785029668_69986447076400'
app/views/projects/merge_requests/_merge_requests.html.haml:3:in `_app_views_projects_merge_requests__merge_requests_html_haml__3166995607600430249_69986443199900'
app/views/projects/merge_requests/index.html.haml:14:in `_app_views_projects_merge_requests_index_html_haml__186508081203370897_69986441374200'
app/controllers/projects/merge_requests_controller.rb:36:in `index'