[INFO] cloning repository https://github.com/deagahelio/flacwand
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/deagahelio/flacwand" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdeagahelio%2Fflacwand", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdeagahelio%2Fflacwand'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0e8f7b7ccd30b673be9f1f27233cd1c7f56a2315
[INFO] testing deagahelio/flacwand against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdeagahelio%2Fflacwand" "/workspace/builds/worker-107/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-107/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/deagahelio/flacwand 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 git repo https://github.com/deagahelio/flacwand
[INFO] finished tweaking git repo https://github.com/deagahelio/flacwand
[INFO] tweaked toml for git repo https://github.com/deagahelio/flacwand written to /workspace/builds/worker-107/source/Cargo.toml
[INFO] crate git repo https://github.com/deagahelio/flacwand 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]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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] 914907e757b1219954807bd2a3161ac252d2eb4c3834baa6da2b167c0ea28a26
[INFO] running `Command { std: "docker" "start" "-a" "914907e757b1219954807bd2a3161ac252d2eb4c3834baa6da2b167c0ea28a26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "914907e757b1219954807bd2a3161ac252d2eb4c3834baa6da2b167c0ea28a26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "914907e757b1219954807bd2a3161ac252d2eb4c3834baa6da2b167c0ea28a26", kill_on_drop: false }`
[INFO] [stdout] 914907e757b1219954807bd2a3161ac252d2eb4c3834baa6da2b167c0ea28a26
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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] 04b670d07cea702d22fda15b59cb6bdd4945f0790c059ec895c33dc49301b6f1
[INFO] running `Command { std: "docker" "start" "-a" "04b670d07cea702d22fda15b59cb6bdd4945f0790c059ec895c33dc49301b6f1", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling num-traits v0.2.2
[INFO] [stderr]    Compiling libc v0.2.40
[INFO] [stderr]    Compiling rustc-serialize v0.3.24
[INFO] [stderr]    Compiling cfg-if v0.1.2
[INFO] [stderr]    Compiling byteorder v1.2.2
[INFO] [stderr]    Compiling argparse v0.2.1
[INFO] [stderr]    Compiling log v0.4.1
[INFO] [stderr]    Compiling log v0.3.9
[INFO] [stderr]    Compiling rand v0.4.2
[INFO] [stderr]    Compiling num-integer v0.1.36
[INFO] [stderr]    Compiling num-iter v0.1.35
[INFO] [stderr]    Compiling num-bigint v0.1.43
[INFO] [stderr]    Compiling num-complex v0.1.43
[INFO] [stderr]    Compiling num-rational v0.1.42
[INFO] [stderr]    Compiling num v0.1.42
[INFO] [stderr]    Compiling metaflac v0.1.8
[INFO] [stderr]    Compiling flacwand v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(panic_info_message)]
[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 `flacwand` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "04b670d07cea702d22fda15b59cb6bdd4945f0790c059ec895c33dc49301b6f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04b670d07cea702d22fda15b59cb6bdd4945f0790c059ec895c33dc49301b6f1", kill_on_drop: false }`
[INFO] [stdout] 04b670d07cea702d22fda15b59cb6bdd4945f0790c059ec895c33dc49301b6f1