Table with uuid field not exported to GeoPackage

[MarkusHesse42]

I created a little test table with uuid field in postgres like this:

CREATE TABLE ga.test_uuid
(
  system_id bigint NOT NULL,
  material character varying(15),
  uuid uuid DEFAULT uuid_generate_v1(),
  d_leitung_in_betrieb geometry(LineString,31468)
)

an filled it with some test records. The import to geogig repository was successful.
But when I try to export to GeoPackage I get an error message:

geogig geopkg export -i test_uuid test_uuid
Cannot create new table in database

geogig.log contails the following error message:

2017-11-23 12:55:59,540 WARN [main] o.g.jdbc [JDBCDataStore.java:756] No mapping for java.util.UUID
2017-11-23 12:55:59,546 ERROR [main] o.l.g.c.GeogigCLI [GeogigCLI.java:390] Cannot create new table in database
java.lang.RuntimeException: Unable to map uuid( java.util.UUID)
        at org.geotools.jdbc.JDBCDataStore.createTableSQL(JDBCDataStore.java:2263) ~[gt-jdbc-18.0.jar:na]
        at org.geotools.jdbc.JDBCDataStore.createSchema(JDBCDataStore.java:786) ~[gt-jdbc-18.0.jar:na]
        at org.geotools.jdbc.JDBCDataStore.createSchema(JDBCDataStore.java:144) ~[gt-jdbc-18.0.jar:na]
        at org.locationtech.geogig.geotools.cli.DataStoreExport.exportInternal(DataStoreExport.java:128) ~[geogig-geotools-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]
        at org.locationtech.geogig.geotools.cli.DataStoreExport.runInternal(DataStoreExport.java:99) ~[geogig-geotools-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]
        at org.locationtech.geogig.geotools.cli.geopkg.GeopkgExport.runInternal(GeopkgExport.java:75) ~[geogig-geotools-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]
        at org.locationtech.geogig.cli.AbstractCommand.run(AbstractCommand.java:68) ~[geogig-cli-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]
        at org.locationtech.geogig.cli.GeogigCLI.executeInternal(GeogigCLI.java:532) ~[geogig-cli-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]
        at org.locationtech.geogig.cli.GeogigCLI.execute(GeogigCLI.java:368) ~[geogig-cli-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]
        at org.locationtech.geogig.cli.app.CLI.run(CLI.java:95) [geogig-cli-app-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]
        at org.locationtech.geogig.cli.app.CLI.main(CLI.java:113) [geogig-cli-app-1.3-SNAPSHOT.jar:1.3-SNAPSHOT]

The GeoPackage DB (database.gpkg) is created but does not contain the table test_uuid.