[INFO] fetching crate openraft 0.6.4...
[INFO] testing openraft-0.6.4 against 1.59.0 for beta-1.60-1
[INFO] extracting crate openraft 0.6.4 into /workspace/builds/worker-19/source
[INFO] validating manifest of crates.io crate openraft 0.6.4 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 openraft 0.6.4
[INFO] finished tweaking crates.io crate openraft 0.6.4
[INFO] tweaked toml for crates.io crate openraft 0.6.4 written to /workspace/builds/worker-19/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] [stderr]     Blocking waiting for file lock on package cache
[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] [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] 0b1984f0ffec10447b94d03ca824c1b2b84c57caa91c98a6b15c17f95853bde8
[INFO] running `Command { std: "docker" "start" "-a" "0b1984f0ffec10447b94d03ca824c1b2b84c57caa91c98a6b15c17f95853bde8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0b1984f0ffec10447b94d03ca824c1b2b84c57caa91c98a6b15c17f95853bde8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0b1984f0ffec10447b94d03ca824c1b2b84c57caa91c98a6b15c17f95853bde8", kill_on_drop: false }`
[INFO] [stdout] 0b1984f0ffec10447b94d03ca824c1b2b84c57caa91c98a6b15c17f95853bde8
[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] 986e3ddb1237cce6de99f669a318a7cda524438541390cd1a056180d0b3a8911
[INFO] running `Command { std: "docker" "start" "-a" "986e3ddb1237cce6de99f669a318a7cda524438541390cd1a056180d0b3a8911", 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 unicode-segmentation v1.9.0
[INFO] [stderr]    Compiling vec_map v0.8.2
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling utf8-width v0.1.5
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling tracing-attributes v0.1.19
[INFO] [stderr]    Compiling pin-project-internal v1.0.10
[INFO] [stderr]    Compiling tokio-macros v1.7.0
[INFO] [stderr]    Compiling derive_more v0.99.17
[INFO] [stderr]    Compiling futures-util v0.3.21
[INFO] [stderr]    Compiling byte-unit v4.0.13
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling clap v2.34.0
[INFO] [stderr]    Compiling tokio v1.17.0
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]    Compiling pin-project v1.0.10
[INFO] [stderr]    Compiling tracing v0.1.31
[INFO] [stderr]    Compiling tracing-futures v0.2.5
[INFO] [stderr]    Compiling futures-executor v0.3.21
[INFO] [stderr]    Compiling futures v0.3.21
[INFO] [stderr]    Compiling structopt v0.3.26
[INFO] [stderr]    Compiling openraft v0.6.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(backtrace)]
[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 `openraft` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "986e3ddb1237cce6de99f669a318a7cda524438541390cd1a056180d0b3a8911", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "986e3ddb1237cce6de99f669a318a7cda524438541390cd1a056180d0b3a8911", kill_on_drop: false }`
[INFO] [stdout] 986e3ddb1237cce6de99f669a318a7cda524438541390cd1a056180d0b3a8911