[Pkg-rust-maintainers] Bug#1030383: rust-backoff: autopkgtest failure

[Adrian Bunk]

Source: rust-backoff
Version: 0.4.0-2
Severity: serious

https://ci.debian.net/data/autopkgtest/testing/amd64/r/rust-backoff/30821230/log.gz

...
error[E0428]: the name `rt_sleeper` is defined multiple times
   --> src/future.rs:211:1
    |
206 | fn rt_sleeper() -> impl Sleeper {
    | ------------------------------- previous definition of the value `rt_sleeper` here
...
211 | fn rt_sleeper() -> impl Sleeper {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `rt_sleeper` redefined here
    |
    = note: `rt_sleeper` must be defined only once in the value namespace of this module

error: Feature "tokio" and "async-std" cannot be enabled at the same time
   --> src/future.rs:203:1
    |
203 | compile_error!("Feature \"tokio\" and \"async-std\" cannot be enabled at the same time");
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0428`.
error: could not compile `backoff` due to 2 previous errors

Caused by:
  process didn't exit successfully: `CARGO=/usr/bin/cargo CARGO_CRATE_NAME=backoff CARGO_MANIFEST_DIR=/usr/share/cargo/registry/backoff-0.4.0 CARGO_PKG_AUTHORS='Tibor Benke <ihrwein at gmail.com>' CARGO_PKG_DESCRIPTION='Retry operations with exponential backoff policy.
  ' CARGO_PKG_HOMEPAGE='https://github.com/ihrwein/backoff' CARGO_PKG_LICENSE=MIT/Apache-2.0 CARGO_PKG_LICENSE_FILE='' CARGO_PKG_NAME=backoff CARGO_PKG_REPOSITORY='https://github.com/ihrwein/backoff' CARGO_PKG_RUST_VERSION='' CARGO_PKG_VERSION=0.4.0 CARGO_PKG_VERSION_MAJOR=0 CARGO_PKG_VERSION_MINOR=4 CARGO_PKG_VERSION_PATCH=0 CARGO_PKG_VERSION_PRE='' CARGO_PRIMARY_PACKAGE=1 LD_LIBRARY_PATH='/tmp/tmp.PnAdkNr0YP/target/debug/deps:/usr/lib' rustc --crate-name backoff --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="async-std"' --cfg 'feature="async_std_1"' --cfg 'feature="default"' --cfg 'feature="futures"' --cfg 'feature="futures-core"' --cfg 'feature="pin-project-lite"' --cfg 'feature="tokio"' --cfg 'feature="tokio_1"' -C metadata=b1aecb5deee08c17 -C extra-filename=-b1aecb5deee08c17 --out-dir /tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps --target x86_64-unknown-linux-gnu -C incremental=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/incremental -L dependency=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps -L dependency=/tmp/tmp.PnAdkNr0YP/target/debug/deps --extern async_std_1=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps/libasync_std-dbe038de9229307c.rmeta --extern futures_core=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps/libfutures_core-5edd52c7e06cbc53.rmeta --extern getrandom=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps/libgetrandom-3730c6758a54504b.rmeta --extern instant=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps/libinstant-77cf826c3e7a2460.rmeta --extern pin_project_lite=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps/libpin_project_lite-4a8436a89a06ca53.rmeta --extern rand=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps/librand-c436e0aad7c5d309.rmeta --extern tokio_1=/tmp/tmp.PnAdkNr0YP/target/x86_64-unknown-linux-gnu/debug/deps/libtokio-0d8d3208d1463cc9.rmeta -C debuginfo=2 --cap-lints warn -C linker=x86_64-linux-gnu-gcc -C link-arg=-Wl,-z,relro --remap-path-prefix /usr/share/cargo/registry/backoff-0.4.0=/usr/share/cargo/registry/backoff-0.4.0 --remap-path-prefix /tmp/tmp.PnAdkNr0YP/registry=/usr/share/cargo/registry` (exit status: 1)
warning: build failed, waiting for other jobs to finish...
autopkgtest [15:20:51]: test rust-backoff:@: -----------------------]
autopkgtest [15:20:51]: test rust-backoff:@:  - - - - - - - - - - results - - - - - - - - - -
rust-backoff:@       FAIL non-zero exit status 101
...
autopkgtest [15:25:39]: @@@@@@@@@@@@@@@@@@@@ summary
rust-backoff:@       FAIL non-zero exit status 101
librust-backoff-dev:async-std PASS
librust-backoff-dev:async_std_1 PASS
librust-backoff-dev:default PASS
librust-backoff-dev:futures PASS
librust-backoff-dev:futures-core PASS
librust-backoff-dev:pin-project-lite PASS
librust-backoff-dev:tokio PASS
librust-backoff-dev:tokio_1 PASS
librust-backoff-dev: PASS