When importing builds.xml data into 1.3.1, I get the following error:
ERROR 23505: The statement was aborted because it would have caused a duplicate key value in a unique or primary key constraint or unique index identified by 'INSTALLATION_PK' defined on 'INSTALLATION'.
To reproduce, create a 'backups' directory, save the attached builds.xml file into it, and execute:
java -Xmx512m -jar data-management-cli-1.3.1-app.jar -buildsJdbcUrl jdbc:derby:/path/to/apache-continuum-1.3.1/data/databases/continuum/ -mode IMPORT -directory backups
The attached builds.xml was exported from a Continuum 1.2 instance using data-management 126.96.36.199.
If you edit builds.xml and delete the <installations> ... </installations> then the import will complete without error.