[INFO] fetching crate directory-tree 0.0.1...
[INFO] testing directory-tree-0.0.1 against 1.59.0 for beta-1.60-1
[INFO] extracting crate directory-tree 0.0.1 into /workspace/builds/worker-101/source
[INFO] validating manifest of crates.io crate directory-tree 0.0.1 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 directory-tree 0.0.1
[INFO] finished tweaking crates.io crate directory-tree 0.0.1
[INFO] tweaked toml for crates.io crate directory-tree 0.0.1 written to /workspace/builds/worker-101/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-101/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-101/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] 615a65f6c3d4dc43cdf5b08c557f1ee18b8497b3129781a0c40fa4034fc37c1c
[INFO] running `Command { std: "docker" "start" "-a" "615a65f6c3d4dc43cdf5b08c557f1ee18b8497b3129781a0c40fa4034fc37c1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "615a65f6c3d4dc43cdf5b08c557f1ee18b8497b3129781a0c40fa4034fc37c1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "615a65f6c3d4dc43cdf5b08c557f1ee18b8497b3129781a0c40fa4034fc37c1c", kill_on_drop: false }`
[INFO] [stdout] 615a65f6c3d4dc43cdf5b08c557f1ee18b8497b3129781a0c40fa4034fc37c1c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-101/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-101/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] 2d92115c68aa32a298415ad9cc14d6cb1cb9dbe2e7088ca61eff9c67f4433efa
[INFO] running `Command { std: "docker" "start" "-a" "2d92115c68aa32a298415ad9cc14d6cb1cb9dbe2e7088ca61eff9c67f4433efa", 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] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling neon-build v0.8.3
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling serde_json v1.0.79
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling cslice v0.2.0
[INFO] [stderr]    Compiling ryu v1.0.9
[INFO] [stderr]    Compiling itoa v1.0.1
[INFO] [stderr]    Compiling libloading v0.6.7
[INFO] [stderr]    Compiling neon-runtime v0.8.3
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling neon v0.8.3
[INFO] [stderr]    Compiling neon-macros v0.8.3
[INFO] [stderr]    Compiling directory-tree v0.0.1 (/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] warning: unused import: `serde_json`
[INFO] [stdout]  --> src/lib.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[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 `directory-tree` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "2d92115c68aa32a298415ad9cc14d6cb1cb9dbe2e7088ca61eff9c67f4433efa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2d92115c68aa32a298415ad9cc14d6cb1cb9dbe2e7088ca61eff9c67f4433efa", kill_on_drop: false }`
[INFO] [stdout] 2d92115c68aa32a298415ad9cc14d6cb1cb9dbe2e7088ca61eff9c67f4433efa