[Pkg-rust-maintainers] Bug#980193: Bug#980193: rust-flate2: autopkgtest regression in testing: [librust-flate2-dev] build failed

[peter green]

This test has never passed, it failed back in December 2019, then was
neutral for some time, before returning to failure recently/

Unfortunately debci doesn't keep logs long-term, but I suspect that
the test was neutral due to unsatisfiable test dependencies.

The first error in the log is
> 
> [crossbeam-utils 0.7.2] error[E0412]: cannot find type `AtomicU128` in module `core::sync::atomic`
> [crossbeam-utils 0.7.2]     --> <anon>:1:38
> [crossbeam-utils 0.7.2]      |
> [crossbeam-utils 0.7.2] 1    |   pub type Probe = core::sync::atomic::AtomicU128;
> [crossbeam-utils 0.7.2]      |                                        ^^^^^^^^^^ help: a struct with a similar name exists: `AtomicU16`
> [crossbeam-utils 0.7.2] 
> [crossbeam-utils 0.7.2] error: aborting due to previous error
> [crossbeam-utils 0.7.2] 
> [crossbeam-utils 0.7.2] For more information about this error, try `rustc --explain E0412`.

But after some googling I belive this is a false positive.

The real errors seem to start at.

> error[E0433]: failed to resolve: use of undeclared crate or module `miniz_oxide`
>  --> src/ffi/rust.rs:6:5
>   |
> 6 | use miniz_oxide::deflate::core::CompressorOxide;
>   |     ^^^^^^^^^^^ use of undeclared crate or module `miniz_oxide`

I suspect this is a case of a crate that is simply not buildable
in a plain no-default-features configuration.