[Pkg-rust-maintainers] Bug#1080480: rust-merge: most autopkgtests fail

[Colin Watson]

Source: rust-merge
Version: 0.1.0-1
Severity: serious
Justification: https://release.debian.org/testing/rc_policy.txt 6(a)

https://ci.debian.net/packages/r/rust-merge/testing/amd64/ appears to
have always failed; it looks as though rust-merge:@ and
librust-merge-dev:default succeed but everything else fails.

librust-merge-dev:derive fails with:

  error[E0433]: failed to resolve: could not find `vec` in `merge`
    --> examples/user.rs:11:31
     |
  11 |     #[merge(strategy = merge::vec::append)]
     |                               ^^^ could not find `vec` in `merge`
     |
  note: found an item that was configured out
    --> /usr/share/cargo/registry/merge-0.1.0/src/lib.rs:205:9
     = note: the item is gated behind the `std` feature
  
  For more information about this error, try `rustc --explain E0433`.
  error: could not compile `merge` (example "user" test) due to 1 previous error

librust-merge-dev:merge_derive, librust-merge-dev:num,
librust-merge-dev:num-traits, librust-merge-dev:std, and
librust-merge-dev: fail with a bunch of errors starting with:

  error: cannot find derive macro `Merge` in this scope
   --> examples/user.rs:6:10
    |
  6 | #[derive(Merge)]
    |          ^^^^^
    |
  note: `Merge` is imported here, but it is only a trait, without a derive macro
   --> examples/user.rs:4:5
    |
  4 | use merge::Merge;
    |     ^^^^^^^^^^^^
  help: consider importing this derive macro

There've been no upstream commits since 2020-09-21, only one upstream
release ever which was on 2020-09-01, and there are no
reverse-dependencies.  Should we just remove it?

-- 
Colin Watson (he/him)                              [cjwatson at debian.org]