snappy rollback accepts junk version argument

[Timothy R. Chavez]

Calling 'snappy rollback' with no argument produces an error:

ubuntu@localhost:~$ snappy versions
Part Tag Installed Available Fingerprint Active
ubuntu-core edge 141 - 7f068cb4fa876c *
docker edge 1.3.2.007 - b1f2f85e77adab *
ubuntu@localhost:~$ snappy rollback
usage: Usage:snappy rollback [-h] args [args ...] [args [args ...]]

I think it'd be reasonable to expect it to rollback to N-1, which if you pass it a junk argument like "FOO", it will do just that:

Usage:snappy rollback: error: the following arguments are required: args, args
ubuntu@localhost:~$ snappy rollback FOO
Rolling back ubuntu-core: (edge 141 7f068cb4fa876c -> edge 140 184ad1e863e947)
Reboot to use the new ubuntu-core.
ubuntu@localhost:~$

[Alexander Sack (asac)]

we are currently iterating on the general primitives of snappy runtime command where we will take this into account; we are playing with approach that wouldn't have rollback, but something else cool that feels more natural etc.... so stay tuned on announces.

marking medium prio because we might just solve this different (if we stick to rollback this certainly is a big problem).

[Michael Vogt (mvo)]

$ sudo snappy rollback
need package name argument
ubuntu@localhost:~$ sudo snappy rollback hello-world
no version to rollback to
ubuntu@localhost:~$ sudo snappy rollback hello-world FOO
Can not find hello-world with version FOO