[Pkg-rust-maintainers] Bug#1026635: rust-packed-simd: FTBFS: dh_auto_test: error: /usr/share/cargo/bin/cargo build returned exit code 101

[Peter Green]

> 
> During a rebuild of all packages in sid, your package failed to build
> on amd64.

I make the following observations about this package.

* It relies on perma-unstable rustc features and this is the third time it
   has broken in the last two years due to changes in rustc.
* It has no long-term future, the future of "portable simd" is as a feature
   in the standard library "std::simd". This is also an unstable feature at
   present but at least has a path to stabilization.
* The current development team does not have access to the packed-simd crate
   on crates.io, so new releases are being released under the alternate crate
   name "packed-simd2".
* No applications in Debian currently use it, the only remaining reverse
   dependencies are optional features in the encoding-rs, grep-searcher and
   grep crates.
* The upstream author of those crates said in a recent commit message
   "I'm *very* close to just removing the 'simd-accel' feature altogether."

Personally I think it's time for this package to go. Unless someone
expresses an intent to fix this package, I intend to patch the encoding-rs
grep-searcher and grep crates to remove the "simd-accel" feature allowing
this package to be autoremoved from testing without taking any applications
with it.