Juju does not recommend help when malformed constraints are encountered

[Tim McNamara]

Assuming that we've bootstrapped correctly, here is an example session using Juju 2.6rc1:

$ juju add-machine --constraints arch
ERROR malformed constraint "arch"

Ideally, users would be presented with some recommended actions. Perhaps

 - list valid constraints, e.g. "valid values are: [amd64]"
 - refer to https://docs.jujucharms.com/2.5/en/reference-constraints
 - refer to a "juju help" topic with the reference info (does this exist?)

[Canonical Juju QA Bot (juju-qa-bot)]

This bug has not been updated in 2 years, so we're marking it Low importance. If you believe this is incorrect, please update the importance.