[INFO] fetching crate async-iterator 2.2.0...
[INFO] testing async-iterator-2.2.0 against 1.76.0 for beta-1.77-1
[INFO] extracting crate async-iterator 2.2.0 into /workspace/builds/worker-1-tc1/source
[INFO] validating manifest of crates.io crate async-iterator 2.2.0 on toolchain 1.76.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate async-iterator 2.2.0
[INFO] finished tweaking crates.io crate async-iterator 2.2.0
[INFO] tweaked toml for crates.io crate async-iterator 2.2.0 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4e65ddfd864cc856112c52e5d5c766f3bc35b3b160ea3a57c7c2cb98bdb1dced
[INFO] running `Command { std: "docker" "start" "-a" "4e65ddfd864cc856112c52e5d5c766f3bc35b3b160ea3a57c7c2cb98bdb1dced", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4e65ddfd864cc856112c52e5d5c766f3bc35b3b160ea3a57c7c2cb98bdb1dced", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e65ddfd864cc856112c52e5d5c766f3bc35b3b160ea3a57c7c2cb98bdb1dced", kill_on_drop: false }`
[INFO] [stdout] 4e65ddfd864cc856112c52e5d5c766f3bc35b3b160ea3a57c7c2cb98bdb1dced
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 56a88c20d8ffe1137083f1b9ab08ae5e045da77e48c504b73eb12beb92bd27ef
[INFO] running `Command { std: "docker" "start" "-a" "56a88c20d8ffe1137083f1b9ab08ae5e045da77e48c504b73eb12beb92bd27ef", kill_on_drop: false }`
[INFO] [stderr]    Compiling async-iterator v2.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:22:1
[INFO] [stdout]    |
[INFO] [stdout] 22 | #![feature(return_position_impl_trait_in_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `return_position_impl_trait_in_trait` has been stable since `1.75.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:23:1
[INFO] [stdout]    |
[INFO] [stdout] 23 | #![feature(async_fn_in_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `async_fn_in_trait` has been stable since `1.75.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `return_position_impl_trait_in_trait` has been stable since 1.75.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:22:12
[INFO] [stdout]    |
[INFO] [stdout] 22 | #![feature(return_position_impl_trait_in_trait)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `async_fn_in_trait` has been stable since 1.75.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:23:12
[INFO] [stdout]    |
[INFO] [stdout] 23 | #![feature(async_fn_in_trait)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `async-iterator` (lib) due to 3 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "56a88c20d8ffe1137083f1b9ab08ae5e045da77e48c504b73eb12beb92bd27ef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56a88c20d8ffe1137083f1b9ab08ae5e045da77e48c504b73eb12beb92bd27ef", kill_on_drop: false }`
[INFO] [stdout] 56a88c20d8ffe1137083f1b9ab08ae5e045da77e48c504b73eb12beb92bd27ef
