Re: [BuildStream] bst CLI design and consistency (UI)

[Paul Sherwood <paul sherwood codethink co uk>]

Hi Chandan,
On 2018-11-30 19:44, Chandan Singh wrote:
> As we have been making some breaking changes to the bst CLI in the 1.4 
> cycle,
> various questions have come up. We have been trying to answer them in 
> isolation
> so far, it has been difficult to do so in the absence of high-level 
> design
> goals. With this thread, I am hoping we can take a more holistic 
> approach to
> designing the CLI in a way that is consistent and intuitive.

I can't usefully comment on the details, but I have two things I'd like 
to say based on my strange 'helicopter perspective' of buildstream:

1) ISTM that from a user-perspective maintaining forward/backward 
compatibility of CLI is significantly less important than several other 
things, for example:
- build/integration integrity
- minimising wasted user time
- cache-key algorithm versioning
- metadata file format versioning and compatibility

IME breakages in format, and/or being surprised by cache reconstruction 
or huge downloads can be extremely frustrating and can prevent users 
from upgrading. For CLI, users can always run --help or ask 'man' after 
all

2) if we are changing/improving CLI, would it make sense to consider 
overhauling our nomenclature and commands to align them with bazel? 
We're already working towards alignment of some technologies, and making 
it easier for bazel users to understand and drive bst (and vice versa) 
would seem like a clear benefit.

br
Paul