Setting up developer environment (db, fixtures) fails

Running rake dev:setup will setup developer environment (db, fixtures) but the seed will fail when importing 24_forks.rb with the following error:

== Seed from /path/to/gdk/gitlab/db/fixtures/development/24_forks.rb
rake aborted!
ActiveRecord::NotNullViolation: PG::NotNullViolation: ERROR:  null value in column "project_id" violates not-null constraint
DETAIL:  Failing row contains (2, 1, null, 2).
: INSERT INTO "fork_network_members" ("fork_network_id", "forked_from_project_id") VALUES ($1, $2) RETURNING "id"