[Pkg-rust-maintainers] Bug#1053556: dh-cargo: should provide a build() method

[Jeremy Bícha]

Control: tags 1050769 +patch

> IMHO it is a dh-cargo bug (see #1053556[1]) which must be fixed before
> greetd's debian/rules can be updated to use dh_auto_build.

No, greetd needs to build itself correctly regardless of whether there
are helper functions available.

The 2 most common types of projects using dh-cargo are
1) Rust crates which are shipped as uncompiled source code
2) Rust apps which have their own build system, usually meson

In both those cases, dh_auto_build works correctly already.

greetd doesn't fall into those cases so needs to implement the build
and install steps itself. It already handles the install. And I've
submitted a merge proposal for it to handle the build.

https://salsa.debian.org/debian/greetd/-/merge_requests/4

Thank you,
Jeremy Bícha