[INFO] fetching crate acm 0.1.4...
[INFO] testing acm-0.1.4 against 1.59.0 for beta-1.60-1
[INFO] extracting crate acm 0.1.4 into /workspace/builds/worker-19/source
[INFO] validating manifest of crates.io crate acm 0.1.4 on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate acm 0.1.4
[INFO] finished tweaking crates.io crate acm 0.1.4
[INFO] tweaked toml for crates.io crate acm 0.1.4 written to /workspace/builds/worker-19/source/Cargo.toml
[INFO] crate crates.io crate acm 0.1.4 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 73c471db7cc7de6fa6b3a9de4e31ca74c95cf01dc8fe8e4a02cfc50ed45a010e
[INFO] running `Command { std: "docker" "start" "-a" "73c471db7cc7de6fa6b3a9de4e31ca74c95cf01dc8fe8e4a02cfc50ed45a010e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "73c471db7cc7de6fa6b3a9de4e31ca74c95cf01dc8fe8e4a02cfc50ed45a010e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "73c471db7cc7de6fa6b3a9de4e31ca74c95cf01dc8fe8e4a02cfc50ed45a010e", kill_on_drop: false }`
[INFO] [stdout] 73c471db7cc7de6fa6b3a9de4e31ca74c95cf01dc8fe8e4a02cfc50ed45a010e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5815433c7cb2afdf98fb7a9f7297034ce1c2590acb8dee71292bc459e5f267cc
[INFO] running `Command { std: "docker" "start" "-a" "5815433c7cb2afdf98fb7a9f7297034ce1c2590acb8dee71292bc459e5f267cc", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling libc v0.2.54
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling cfg-if v0.1.9
[INFO] [stderr]    Compiling rustc-demangle v0.1.14
[INFO] [stderr]    Compiling unicode-width v0.1.5
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling vec_map v0.8.1
[INFO] [stderr]    Compiling bitflags v1.0.4
[INFO] [stderr]    Compiling yaml-rust v0.3.5
[INFO] [stderr]    Compiling ansi_term v0.11.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-bigint v0.3.2
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling backtrace v0.3.20
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling atty v0.2.11
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling acm v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/acm.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/acm.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(step_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `acm` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "5815433c7cb2afdf98fb7a9f7297034ce1c2590acb8dee71292bc459e5f267cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5815433c7cb2afdf98fb7a9f7297034ce1c2590acb8dee71292bc459e5f267cc", kill_on_drop: false }`
[INFO] [stdout] 5815433c7cb2afdf98fb7a9f7297034ce1c2590acb8dee71292bc459e5f267cc