[INFO] fetching crate arr 0.6.1...
[INFO] testing arr-0.6.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate arr 0.6.1 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate arr 0.6.1 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate arr 0.6.1
[INFO] finished tweaking crates.io crate arr 0.6.1
[INFO] tweaked toml for crates.io crate arr 0.6.1 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 740686de396a2297d3e15dc7809099949039cf95b1e3d5a6793521a478a3650c
[INFO] running `Command { std: "docker" "start" "-a" "740686de396a2297d3e15dc7809099949039cf95b1e3d5a6793521a478a3650c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "740686de396a2297d3e15dc7809099949039cf95b1e3d5a6793521a478a3650c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "740686de396a2297d3e15dc7809099949039cf95b1e3d5a6793521a478a3650c", kill_on_drop: false }`
[INFO] [stdout] 740686de396a2297d3e15dc7809099949039cf95b1e3d5a6793521a478a3650c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ed673ca36abe29a4dae4e861b783571b2885d3671b18513c3c4cf03cd3f96855
[INFO] running `Command { std: "docker" "start" "-a" "ed673ca36abe29a4dae4e861b783571b2885d3671b18513c3c4cf03cd3f96855", kill_on_drop: false }`
[INFO] [stderr]    Compiling arr v0.6.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:33:1
[INFO] [stdout]    |
[INFO] [stdout] 33 | #![feature(const_generics)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_generics` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:33:12
[INFO] [stdout]    |
[INFO] [stdout] 33 | #![feature(const_generics)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]    = note: see issue #44580 <https://github.com/rust-lang/rust/issues/44580> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning 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 `arr` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "ed673ca36abe29a4dae4e861b783571b2885d3671b18513c3c4cf03cd3f96855", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ed673ca36abe29a4dae4e861b783571b2885d3671b18513c3c4cf03cd3f96855", kill_on_drop: false }`
[INFO] [stdout] ed673ca36abe29a4dae4e861b783571b2885d3671b18513c3c4cf03cd3f96855