[INFO] fetching crate openraft 0.6.4...
[INFO] testing openraft-0.6.4 against 1.60.0 for beta-1.61-1
[INFO] extracting crate openraft 0.6.4 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate openraft 0.6.4 on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "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-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "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" "+1.60.0" "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 byte-unit v4.0.14
[INFO] [stderr]   Downloaded utf8-width v0.1.6
[INFO] [stderr]   Downloaded memstore v0.2.0
[INFO] [stderr]   Downloaded async-raft v0.6.1
[INFO] [stderr]   Downloaded tracing-appender v0.2.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 362a98ca40f141427f2a5f8f25a32ae780dfa41e9a248c1f09f30ce3af4a3d8f
[INFO] running `Command { std: "docker" "start" "-a" "362a98ca40f141427f2a5f8f25a32ae780dfa41e9a248c1f09f30ce3af4a3d8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "362a98ca40f141427f2a5f8f25a32ae780dfa41e9a248c1f09f30ce3af4a3d8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "362a98ca40f141427f2a5f8f25a32ae780dfa41e9a248c1f09f30ce3af4a3d8f", kill_on_drop: false }`
[INFO] [stdout] 362a98ca40f141427f2a5f8f25a32ae780dfa41e9a248c1f09f30ce3af4a3d8f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d3b7baf0036b5a69e3e9413172911171857eabdb9732f805e058f16d00f3da49
[INFO] running `Command { std: "docker" "start" "-a" "d3b7baf0036b5a69e3e9413172911171857eabdb9732f805e058f16d00f3da49", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.91
[INFO] [stderr]    Compiling async-trait v0.1.53
[INFO] [stderr]    Compiling convert_case v0.4.0
[INFO] [stderr]    Compiling utf8-width v0.1.6
[INFO] [stderr]    Compiling maplit v1.0.2
[INFO] [stderr]    Compiling futures-core v0.3.21
[INFO] [stderr]    Compiling futures-channel v0.3.21
[INFO] [stderr]    Compiling futures-util v0.3.21
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling getrandom v0.2.6
[INFO] [stderr]    Compiling clap v2.34.0
[INFO] [stderr]    Compiling byte-unit v4.0.14
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling futures-macro v0.3.21
[INFO] [stderr]    Compiling tracing-attributes v0.1.20
[INFO] [stderr]    Compiling pin-project-internal v1.0.10
[INFO] [stderr]    Compiling thiserror-impl v1.0.30
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling tokio-macros v1.7.0
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]    Compiling derive_more v0.99.17
[INFO] [stderr]    Compiling tokio v1.17.0
[INFO] [stderr]    Compiling pin-project v1.0.10
[INFO] [stderr]    Compiling thiserror v1.0.30
[INFO] [stderr]    Compiling structopt v0.3.26
[INFO] [stderr]    Compiling tracing v0.1.33
[INFO] [stderr]    Compiling tracing-futures v0.2.5
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling futures-executor v0.3.21
[INFO] [stderr]    Compiling futures v0.3.21
[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" "d3b7baf0036b5a69e3e9413172911171857eabdb9732f805e058f16d00f3da49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3b7baf0036b5a69e3e9413172911171857eabdb9732f805e058f16d00f3da49", kill_on_drop: false }`
[INFO] [stdout] d3b7baf0036b5a69e3e9413172911171857eabdb9732f805e058f16d00f3da49