Re: [BuildStream] bst show all and bst build all flags

[Phillip Smyth <phillip smyth codethink co uk>]

Hi all,

Just to summarise the contents of the discussion yesterday on 
#buildstream:

Tristan and Jürg believe that currently it would be impossible to have a 
build all command, due to there existing platform dependent elements 
which are guaranteed not to work  in certain cases.

Instead they suggested the option of having a default element, that 
would build if no other element was specified, and for that element to 
be configurable.

This however does not resolve #638 [1] and #640 [2]

I put forward the idea of "soft loading" all elements, and then 
skipping/failing all elements which could not be loaded

Tristan and Jürg believed this could be unreliable and produce 
unexpected behaviour.

Tristan believes that a validation of *everything* is more plausible,
but also suffers from the fact that some fragments won't be reachable 
depending on project options enabled at validation time

Following further discussion with Daniel Silverstone, i'm looking into 
adding a script to `contrib/` which will do a build all and another for 
show all
I'll keep you up to date with my progress on that
Currently my progress is in [3]

[1] https://gitlab.com/BuildStream/buildstream/issues/638
[2] https://gitlab.com/BuildStream/buildstream/issues/640
[3] https://gitlab.com/BuildStream/buildstream/merge_requests/990

Best regards,
Phillip Smyth [Nexus]