[Pkg-rust-maintainers] Bug#1124769: Bug#1124769: rustc: FTBFS rustc in Debian Bookworm because of conflict in build deps

[Sergei Semin]

Oh, I just received your letter that you already reproduced problem
with debootstrap too. Thank you!

В Вт, 06/01/2026 в 21:27 +0100, Fabian Grünbichler пишет:
> Control: reassign -1 src:rustc-web 1.85.0+dfsg3-1~deb12u3
> 
> On Tue, Jan 6, 2026, at 8:41 PM, Sergei Semin wrote:
> > Fabian, hi!
> > 
> > Thank you for such quick answer!
> > 
> > You wrote:
> > 
> > > that sounds like your repository setup is incomplete? did you
> > > maybe
> > forget to also add the corresponding main bookworm repository?
> > 
> > I think my repository setup is complete. [..]
> 
> I haven't tried your exact steps, since I don't use docker in any
> fashion.
> But I can reproduce the issue in a plain bookworm chroot as well,
> it's
> just that sbuild (the official way to build packages) uses a
> different
> (build-)dependency resolver than `apt build-dep`.
> 
> The actual problem is that rustc-web and cargo-web both have a
> Provides:
> for regular rustc and cargo, but cargo-web's one is unversioned, and
> thus
> a versioned build-dependency on both rustc and cargo (which rustc
> has)
> potentially only picks up rustc-web, but not cargo-web, which is an
> invalid combination because of the Conflicts.
> 
> Reassigning accordingly, pochu/adilinger feel free to provide further
> input, I think the correct solution here is to add a version to
> cargo-web's
> Provides line as well, or drop the version from rustc-web's?
> 
> @Sergey: I think you can work around the issue by first installing
> rustc
> and cargo, then running `apt build-dep` again - at least that works
> in my
> reproducer environment.
> 
> Fabian