Subject: Re: [PATCH 0/4] build-system/cargo: Propagations across the crate closure.

From: Jakub Kądziołka <[email-masked]>
Date: Thu, 13 Aug 2020 18:16:38 +0200

On Thu, Aug 13, 2020 at 12:48:43PM +0300, Efraim Flashner wrote:
> I'm going to respond here so the thoughts don't get lost. While it would
> take care of some of the issues we have regarding adding regular inputs
> or propagated-/native- inputs, I don't think this is the way we want to
> go. If we can't figure out how to re-use build artifacts then I'd rather
> copy the go-build-system and install the sources into the output and use
> that as the input for the next package. That would give us the
> build-graph which we really want.

Note that this wouldn't solve all the issues, we would still need
an equivalent for propagated phases, to set any environment variables
necessary.

Moreover, note that the reason the current system was introduced in the
first place was to avoid the quadratic builds. I suppose this is less of
an issue in go-build-system due to the order-of-magnitude difference in
compiler speed on typical source code.

As for re-using build artifacts, once we figure out how to do it, we can
always revert this patch, together with the one that originally added
cargo-inputs. I don't think it's going to be any time soon, though, as
upstream doesn't support this style of building.

Regards,
Jakub Kądziołka