[INFO] fetching crate zerogc-simple 0.2.0-alpha.5...
[INFO] checking zerogc-simple-0.2.0-alpha.5 against 1.55.0 for beta-1.56-3
[INFO] extracting crate zerogc-simple 0.2.0-alpha.5 into /workspace/builds/worker-87/source
[INFO] validating manifest of crates.io crate zerogc-simple 0.2.0-alpha.5 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 zerogc-simple 0.2.0-alpha.5
[INFO] finished tweaking crates.io crate zerogc-simple 0.2.0-alpha.5
[INFO] tweaked toml for crates.io crate zerogc-simple 0.2.0-alpha.5 written to /workspace/builds/worker-87/source/Cargo.toml
[INFO] crate crates.io crate zerogc-simple 0.2.0-alpha.5 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "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-87/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-87/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] 637444ed055da40be0c11ac44ad675b63490fb6f539ed47ca297ac7b404c456f
[INFO] running `Command { std: "docker" "start" "-a" "637444ed055da40be0c11ac44ad675b63490fb6f539ed47ca297ac7b404c456f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "637444ed055da40be0c11ac44ad675b63490fb6f539ed47ca297ac7b404c456f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "637444ed055da40be0c11ac44ad675b63490fb6f539ed47ca297ac7b404c456f", kill_on_drop: false }`
[INFO] [stdout] 637444ed055da40be0c11ac44ad675b63490fb6f539ed47ca297ac7b404c456f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-87/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-87/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" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 70a516bbd7655bfad8a388a279a95e765050f16829a894aa4a87a01c417d69bb
[INFO] running `Command { std: "docker" "start" "-a" "70a516bbd7655bfad8a388a279a95e765050f16829a894aa4a87a01c417d69bb", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.99
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling hashbrown v0.11.2
[INFO] [stderr]    Compiling slog v2.7.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]    Compiling indexmap v1.7.0
[INFO] [stderr]    Compiling memoffset v0.6.4
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]     Checking instant v0.1.10
[INFO] [stderr]     Checking crossbeam-channel v0.5.1
[INFO] [stderr]     Checking lock_api v0.4.4
[INFO] [stderr]     Checking crossbeam-deque v0.8.1
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking dirs-sys-next v0.1.2
[INFO] [stderr]     Checking time v0.1.43
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking dirs-next v2.0.0
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]     Checking term v0.7.0
[INFO] [stderr]     Checking num-integer v0.1.44
[INFO] [stderr]     Checking chrono v0.4.19
[INFO] [stderr]     Checking slog-term v2.8.0
[INFO] [stderr]    Compiling proc-macro-kwargs-derive v0.1.5
[INFO] [stderr]    Compiling proc-macro-kwargs v0.1.5
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/proc-macro-kwargs-0.1.5/src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `proc-macro-kwargs` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "70a516bbd7655bfad8a388a279a95e765050f16829a894aa4a87a01c417d69bb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "70a516bbd7655bfad8a388a279a95e765050f16829a894aa4a87a01c417d69bb", kill_on_drop: false }`
[INFO] [stdout] 70a516bbd7655bfad8a388a279a95e765050f16829a894aa4a87a01c417d69bb
