Re: [BuildStream] How to synchronize nested junctions

[Tristan Van Berkom <tristan vanberkom codethink co uk>]

Hi Chandan,

> On Apr 10, 2019, at 11:56 PM, Chandan Singh <chandan chandansingh net> wrote:
>
> Hi Tristan,
>
> >    "BuildStream uses the junction element name as key to determine
> >     which junctions to merge. It is recommended that the name of a
> >     junction is set to the same as the name of the linked project."
> >
> > I realize that this is really not an obvious thing to realize in
> > practice, maybe we need better messaging around this (and maybe there
> > are still edge cases around this which don't work perfectly and
> > conveniently ?).
> >
> > Maybe even some enhancements are possible around here, I am skeptical
> > about having recursive junction lookups; when the end project wants to
> > address sub-sub project elements, there is already the option of
> > including a matching junction to the sub-sub project in the calling
> > project, using a matching junction element name.
> >
> > Before considering further enhancements, I just wanted to point out the
> > current, existing solution for this.
>
> I agree that we should try the existing solutions before considering
> further enhancements, but I am not sure if we have any existing
> solutions for the use-case that I mentioned. Having a junction
> matching to the sub-sub-project is what we have now, but it requires
> them to be kept in sync. Is there a trick I am missing here? Because I
> don't see a way around keeping the two junctions in sync, without
> enforcing that as an external process.

I see what you mean, I think the current behavior is to error out if the refs do not match ?

Maybe a good solution is to have a way to declare the junction such that I should inherit the ref from the 
matching junctions in subprojects ?

Cheers,
    -Tristan



> Cheers,
> Chandan