Error when restoring from backup to new installation

I’m trying to restore a backup from a working discourse installation to a new (test) discourse installation. It keeps failing with the following errors :

[2020-12-18 12:37:14] ERROR:  relation "github_user_infos" already exists
[2020-12-18 12:37:14] EXCEPTION: psql failed: ERROR:  relation "github_user_infos" already exists