@type t() :: %Sidereon.Terrain.MmapTerrain.TerrainDatumError{
  kind: :terrain | :geoid | :io | :missing_egm96_dac,
  message: String.t() | nil,
  path: String.t() | nil,
  reason: String.t() | nil,
  remediation: String.t() | nil
}