Code review comment for lp:~axwalk/juju-core/sanity-check-constraints

LGTM, thanks.

https://codereview.appspot.com/13632046/diff/49001/environs/interface.go
File environs/interface.go (right):

https://codereview.appspot.com/13632046/diff/49001/environs/interface.go#newcode152
environs/interface.go:152: PrecheckContainer(series string, kind
instance.ContainerType) error
I'm easy wrt series. I think we will one day want to check it, but our
best effort doe not yet include that; I worry a tiny bit that we'll also
want to be checking arch (people might have a legitimate reason to ask
for an i386 kvm machine...) but that's a bit less certain and not worth
the churn. Let it stand as it is.

https://codereview.appspot.com/13632046/diff/49001/errors/errors.go
File errors/errors.go (right):

https://codereview.appspot.com/13632046/diff/49001/errors/errors.go#newcode127
errors/errors.go:127: return
containersUnsupportedError{&errorWrapper{Err: err, Msg: msg}}
Hey, are these tested?

https://codereview.appspot.com/13632046/