root@localhost:~# snappy list
Name                   Date       Version      Developer
canonical-pc           2016-02-02 IOUPJQPTSUYg sideload
xxxx-linux             2016-03-10 IOUPJQdSYYFf sideload
xxxxxx                 2016-03-10 LSdbYGKYWpSg sideload
ubuntu-core            2016-03-11 LSdbTlhCdMHW sideload
root@localhost:~# snappy update ubuntu-core
the given snap is not installed
root@localhost:~#