[Pkg-rust-maintainers] Facilitating Firefox+Rust Linux distro packaging

[Henri Sivonen]

On Thu, Aug 25, 2016 at 11:46 AM, Henri Sivonen <hsivonen at mozilla.com> wrote:
> On Wed, Aug 24, 2016 at 1:47 PM, Henri Sivonen <hsivonen at mozilla.com> wrote:
>> It's best to ask the Thunderbird folks what their plans are.
>
> I asked. (Just now; no reply yet.)
> https://groups.google.com/d/msg/mozilla.dev.apps.thunderbird/sGFe-GGr5XE/rJwF1TKrAAAJ

It looks like it's reasonable to expect Thunderbird to inherit
Firefox's Rust dependency.

On Fri, Aug 26, 2016 at 2:39 PM, Ximin Luo <infinity0 at debian.org> wrote:
>> - By the time ESR requires rustc, it will also require rust-bindgen.
>>   Which in turn requires libclang.
>
> libclang is from LLVM yes? So the above two points would be solved by being able to backport LLVM to Debian stable. *Hopefully* the dependencies (rust-bindgen->libclang, and rustc->llvm) are to the same *version* of LLVM...

There is no sameness requirement arising from the use cases, AFAICT.
rust-bindgen uses the C++ front end from libclang. rustc using the
LLVM back end. (I'm not saying that using the same version won't work.
Just that, AFAICT, there isn't any intrinsic version coupling.)

On Fri, Aug 26, 2016 at 1:48 PM, Mike Hommey <mh at glandium.org> wrote:
> - By the time ESR requires rustc, it will require a very much more
>   recent version of rustc than the one in Debian stable. Rustc currently
>   only be compiled, at best, by the previous version. Which means either
>   building every released version of rustc between the one shipped in
>   Debian stable and the one required by ESR in sequence, or
>   bootstrapping rustc from scratch. (and same again a year later, when
>   the ESR version bumps)

This would be neatly solved by Debian stable updating both Firefox and
rustc every six weeks like Debian stable updates our competitor
Chromium. (This would nicely also eliminate the complication of people
who want to write Rust code having to know to avoid from main and to
go to backports or to rustup.rs instead.)

> At this point, I'm thinking we might as well have a separate archive for
> Firefox only, that would autobuild the latest uploads of llvm, clang,
> rustc and Firefox in a Debian stable build environment.

Building a dependency constellation of the latest (non-ESR) Firefox,
rustc, cargo, llvm and libclang appears to solve the problems, so it
seems like a reasonable solution. Why would it need to be in a
separate archive, though? Chromium already updates every six weeks in
main as opposed to a separate archive. Old Ubuntu LTS seems to be able
to package a newer GCC within their main archive in order to build
non-ESR Firefox: http://packages.ubuntu.com/precise/gcc-mozilla .

-- 
Henri Sivonen
hsivonen at mozilla.com