This page shows how to mark one issue as a duplicate of another in Google Issue Tracker. When you mark an issue as a duplicate, its status is changed to Duplicate and it is considered closed.
You must have Edit Issues permissions for the components that contain both issues in order to mark an issue as a duplicate of another.
Mark an issue as a duplicate
To mark an issue as a duplicate of another:
Open the issue.
In the App Bar near the top of the page, click Mark as Duplicate.
In the text field that appears, you have two options. You can search for the canonical issue (the issue you want to remain active) by typing a search query. Alternatively, you can enter the issue id.
If you searched for the canonical issue, select it from the search results.
Issue Tracker notifies you that the issue has been marked as a duplicate. For example:
Canonical Issue ID set to "19596671", Status set to "Duplicate".
A yellow bar appears below the App Bar and indicates that the issue has been marked as a duplicate of another issue.