Re: [RFC][PATCH 0/3] Experiments with .dsc backend

[Henning Schild <henning.schild@siemens.com>]

Am Mon, 23 Apr 2018 16:21:43 +0300
schrieb Alexander Smirnov <asmirnov@ilbers.de>:

> Hi everybody,
> 
> as it was planned initially, one of the Isar feature is the ability to
> rebuild original Debian packages with/without customizations. Doing
> this manually in classical Yocto/OE style requires manual setting of
> lots of variables and having a copy of Debian patch (*.debian.tar.xz)
> for this package in your recipe's folder. Maintenance of this system
> becomes very complicated.
> 
> I performed a small research regarding bitbake capabilities and found
> an interesting trick: during bitbake parsing stage (in anonymous
> tasks) we could re-construct whole recipe (including tasks and
> variable), and this snapshot will be stored in recipe's dynamic
> context, that is used during pipeline execution.
> 
> This series is just a PoC, lots of issues are still open, like:
>  - Patching upstream packages
>  - Automatic cross-recipe dependency detection to avoid duplications
> in recipe and debian/control files
>  - etc...
> 
> To test this series just run:
> 
>  $ bitbake hello
> 
> After build, in hello workdir there will be a newly-baked identical
> copy of upstream package :-)

Interesting idea, but my personal feeling is that Isar already uses a
lot of bitbake magic and we should maybe try to avoid introducing more
where feasible.

> Feedbacks, ideas, proposals are welcome!

So my feedback would be that the .dsc to recipe step should be put in a
helper tool in the scripts directory. People that want to modifiy
upstream packages would generate an isar-recipe with the tool once.
Modifications in the form of patches could go on top.
Or would this limit the envisioned feature in any way?

I also fear that this could complicate the reproducable build story.

Henning

> With best regards,
> Alex
> 
> Alexander Smirnov (3):
>   buildchroot: Include texinfo to base system
>   classes/dsc: Basic Debian .dsc backend implementation
>   recipes-debian: Add example recipe to test Debian .dsc support
> 
>  meta-isar/recipes-debian/hello/hello.bb          |  10 ++
>  meta/classes/debian-dsc.bbclass                  | 112
> +++++++++++++++++++++++
> meta/recipes-devtools/buildchroot/buildchroot.bb |   3 +- 3 files
> changed, 124 insertions(+), 1 deletion(-) create mode 100644
> meta-isar/recipes-debian/hello/hello.bb create mode 100644
> meta/classes/debian-dsc.bbclass
>