Re: [BuildStream] Cache key instability

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

Hi Daniel,

Thanks for raising this, the choice of using a pickle was arbitrary and
for the sake of performance, if it is not stable then of course it must
be changed.

On Thu, 2019-02-14 at 11:09 +0000, Daniel Silverstone via BuildStream-list wrote:
> Hi all,

[...]
> I propose that we rev the cache key version, and switch from pickling to JSON
> (though I'd entertain a ruamel dump too if that's quick enough) and am seeking
> support for this.  Indeed I intend to file an MR when I have written and tested
> a change to use the built-in JSON implementation providing it isn't a
> *significant* performance impact short-term to do so.

+1 for JSON

Not worth ruamel as this is not a user visible string (we don't really
buy any consistency by using ruamel in this case).

Also, I doubt that it is okay to not fix this just because of a
performance impact.

Cheers,
    -Tristan