NoMethodError: undefined method `commit_shas' for nil:NilClass
https://sentry.gitlab.net/gitlab/gitlabcom/issues/778623/
NoMethodError: undefined method `commit_shas' for nil:NilClass
merge_request.rb:364:in `commit_shas'
merge_request_diff.commit_shas
gitlab/metrics/instrumentation.rb:161:in `block in commit_shas'
.measure { super }
gitlab/metrics/method_call.rb:36:in `measure'
retval = yield
gitlab/metrics/instrumentation.rb:161:in `commit_shas'
.measure { super }
ci/build.rb:508:in `block in merge_request'
merge_request.commit_shas.include?(pipeline.sha)
...
(152 additional frame(s) were not displayed)
NoMethodError: undefined method `commit_shas' for nil:NilClass