[Buildroot] [PATCH] infra: add the transient download mechanism

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

On Thu, 16 Jan 2020 10:01:09 +0000
Nicolas Carrier <nicolas.carrier@orolia.com> wrote:

> Just to be sure I understand, when you say "when TRANSIENT_DOWNLOAD is
> NO.", it'd be the same as if TRANSIENT_DOWNLOAD download is not defined
> at all, right?

Yes.

There is maybe a little bit of an issue in Yann's current
implementation as he does:

	$(if $($(2)_DOWNLOAD_TRANSIENT),-F) \

so in fact, -F would be passed as soon as <pkg>_DOWNLOAD_TRANSIENT is
non-empty, so <pkg>_DOWNLOAD_TRANSIENT = NO would in fact pass -F.

But this bug already exists for <pkg>_GIT_SUBMODULES:

	$(if $($(2)_GIT_SUBMODULES),-r) \

And it is trivial to fix.

> If it's the case, then that seems to me like a good idea, because it
> renders explicit the risk taken by the user when using a branch (which
> can be done unknowingly ATM).

Absolutely.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com