Sometimes the chain of custody report returns an empty CSV

Problem description

For an unknown reason the merge request chain of custody report is sometimes empty.

This happens both on the list all merge commits report and when exporting for just a single merge commit.

Update: This appears to be caused by the MergeRequestFinder ignoring merge requests from subgroups.

Steps to replicate

Internal links.

1. View the dashboard.
2. Export a single report for this commit.

Additional context

Internal link.

See this slack thread for more info.

Implementation plan

• Change the behaviour of the export functionality to include merge requests from subgroups.