What a library's migration version receives.
:repo,:adapter(:postgres,:mysqlor:sqlite),:prefix:library— the library's tracking name:version— the version being run:install_options— the options recorded at install time, with string keys and values (as stored), such as%{"primary_key" => "binary_id"}:backfills— how backfills run in this migration::inlineor:deferred(seePhoenixMountable.Backfill):opts— the options given toup/1ordown/1