Allow BuildStream to be installed in a remote-only mode
Background
Since !626 (merged) was merged, there is a use-case for wanting to install BuildStream only as a remote execution client. This can be quite useful to allow users (and CI pipelines) to do all their builds on a remote build farm without ever having to install any host dependencies.
Thoughts?
Task description
Since setup.py currently enforces this check at install time, we have a few choices if we were to do this:
- Provide a special flag for this using something like
BST_FORCE_BACKEND=remote-execution, or - Remove such checks entirely from the the installation step and move them to at runtime when we want to ensure that we have some kind of sandbox.
Acceptance Criteria
One is able to install BuildStram without having to instally any sandboxing tools locally.
Edited by Chandan Singh