Odd binary id mismatch

Questions & Help Questions
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4

Migration:

defmodule Stats.Repo.Migrations.CreateSourcesTable do
  use Ecto.Migration

  def change do
    create table(:sources) do
      add :nth, :integer, null: false
      add :url, :string, null: false
      add :contents, :text
    end

    create index("sources", [:nth], unique: true)
    create index("sources", [:url], unique: true)
  end
end

Schema:

defmodule Stats.Source do
  use Stats.Schema
  import Ecto.Changeset

  schema "sources" do
    has_many(:meetings, Stats.Meeting)

    field(:nth, :integer)
    field(:url, :string)
    field(:contents, :string)
  end
end