How to duplicate a git repository on gitlab/github without forking?

In gitlab there is functionality out of the box:

1. Go to Settings -> General of existing project
2. Last expanded panel Advanced contains Export button. Click it and then on the top of this page you can see info message Project export started. A download link will be sent by email.
3. Check email. There is following message:

Project NAME_OF_YOUR_EXISTING_PROJECT was exported successfully.

The project export can be downloaded from: SOME_LINK

The download link will expire in 24 hours.

4. Click SOME_LINK and then check the Downloads folder
5. Go to Project - Your projects page
6. Click the button New project
7. Click the Import project box
8. Click the button Gitlab export
9. Click Choose file and select previously downloaded file *.tar.gz
10. Click the button Import project
11. Then you will see Import in progress label.
12. DEAL