[INFO] fetching crate tree-automata 0.1.2...
[INFO] testing tree-automata-0.1.2 against 1.55.0 for beta-1.56-1
[INFO] extracting crate tree-automata 0.1.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate tree-automata 0.1.2 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 tree-automata 0.1.2
[INFO] finished tweaking crates.io crate tree-automata 0.1.2
[INFO] tweaked toml for crates.io crate tree-automata 0.1.2 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate tree-automata 0.1.2 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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded terms v0.1.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] b50af21d069745e4d2f9f835c444c60ff877eb48ef14cb11ce290ec936acb57f
[INFO] running `Command { std: "docker" "start" "-a" "b50af21d069745e4d2f9f835c444c60ff877eb48ef14cb11ce290ec936acb57f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b50af21d069745e4d2f9f835c444c60ff877eb48ef14cb11ce290ec936acb57f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b50af21d069745e4d2f9f835c444c60ff877eb48ef14cb11ce290ec936acb57f", kill_on_drop: false }`
[INFO] [stdout] b50af21d069745e4d2f9f835c444c60ff877eb48ef14cb11ce290ec936acb57f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] c02893c67b352b2a6deefb93c3f4b42585755a88f4d85004dd27c0d262c41d6d
[INFO] running `Command { std: "docker" "start" "-a" "c02893c67b352b2a6deefb93c3f4b42585755a88f4d85004dd27c0d262c41d6d", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.76
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling ppv-lite86 v0.2.9
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling crossbeam-channel v0.4.3
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling terms v0.1.2
[INFO] [stderr]    Compiling tree-automata v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![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 `tree-automata` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "c02893c67b352b2a6deefb93c3f4b42585755a88f4d85004dd27c0d262c41d6d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c02893c67b352b2a6deefb93c3f4b42585755a88f4d85004dd27c0d262c41d6d", kill_on_drop: false }`
[INFO] [stdout] c02893c67b352b2a6deefb93c3f4b42585755a88f4d85004dd27c0d262c41d6d