Re: bst operations from within workspaces

[Jürg Billeter <j bitron ch>]

Hi Daniel,

On Thu, 2017-11-30 at 10:18 +0000, Daniel Playle wrote:
> `bst` currently operates relative to `project.conf` in the project
> directory. This means that when it comes to the current workflow for
> workspaces, one must switch between the workspace and the bst project
> directory as part of the development cycle.
>
> To provide a smoother experience, I'd like to see `bst` also operate
> from within open workspaces. This would require some mapping from the
> workspace to the associated project directory.

I agree, this sounds useful to me.

> To achieve this, we can provide an implicit mapping by opening
> workspaces within a subdirectory of the project directory by default
> (we could call this `bst-workspaces` within the project directory,
> for instance). In this case, we can simply walk up the tree until we
> find the project directory. 

Thinking about this, it may not be ideal that a BuildStream project
directory is identified by a file with the relatively generic name
'project.conf'. However, I don't expect any significant issues with
this in practice and simply walking up the directory hierarchy makes
sense.

This will also be convenient for running `bst` in the elements
subdirectory, and it matches the behavior of git. We should probably
stop walking up the directory hierarchy at filesystem boundaries (git
does the same, if I remember correctly).

I'm not sure whether we really need to define a fixed name for the
subdirectory of the project directory, though. Do you see an issue with
the user simply specifying a path, as is already the case now?

> For the case where a user does not wish to have their workspace
> reside within their project directory, we can read the location of
> the project directory from some environment variable to still afford
> the ability to invoke `bst` in these workspaces.

Yes, this would be similar to GIT_DIR. Sounds straight forward to me.
BST_DIR?

Jürg