[INFO] fetching crate syndicate 0.23.0...
[INFO] testing syndicate-0.23.0 against 1.60.0 for beta-1.61-1
[INFO] extracting crate syndicate 0.23.0 into /workspace/builds/worker-18/source
[INFO] validating manifest of crates.io crate syndicate 0.23.0 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 syndicate 0.23.0
[INFO] finished tweaking crates.io crate syndicate 0.23.0
[INFO] tweaked toml for crates.io crate syndicate 0.23.0 written to /workspace/builds/worker-18/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] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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] 50ea666e0ff1e68c107524f335659d9c08af7825f166597aae537d654b8c8516
[INFO] running `Command { std: "docker" "start" "-a" "50ea666e0ff1e68c107524f335659d9c08af7825f166597aae537d654b8c8516", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "50ea666e0ff1e68c107524f335659d9c08af7825f166597aae537d654b8c8516", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "50ea666e0ff1e68c107524f335659d9c08af7825f166597aae537d654b8c8516", kill_on_drop: false }`
[INFO] [stdout] 50ea666e0ff1e68c107524f335659d9c08af7825f166597aae537d654b8c8516
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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] 71630b7a7a4e954fafc5d11e1970052d523452ca61bd0ddff079e8b67cd205b7
[INFO] running `Command { std: "docker" "start" "-a" "71630b7a7a4e954fafc5d11e1970052d523452ca61bd0ddff079e8b67cd205b7", 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 v1.0.91
[INFO] [stderr]    Compiling futures-sink v0.3.21
[INFO] [stderr]    Compiling convert_case v0.4.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-bigint v0.4.3
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-rational v0.4.0
[INFO] [stderr]    Compiling tracing-core v0.1.25
[INFO] [stderr]    Compiling lock_api v0.4.7
[INFO] [stderr]    Compiling regex-automata v0.1.10
[INFO] [stderr]    Compiling sharded-slab v0.1.4
[INFO] [stderr]    Compiling thread_local v1.1.4
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling parking_lot_core v0.8.5
[INFO] [stderr]    Compiling sha2 v0.9.9
[INFO] [stderr]    Compiling futures-channel v0.3.21
[INFO] [stderr]    Compiling tracing-log v0.1.2
[INFO] [stderr]    Compiling parking_lot v0.11.2
[INFO] [stderr]    Compiling matchers v0.0.1
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-complex v0.4.0
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling num v0.4.0
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling thiserror-impl v1.0.30
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]    Compiling tracing-attributes v0.1.20
[INFO] [stderr]    Compiling futures-macro v0.3.21
[INFO] [stderr]    Compiling tokio-macros v1.7.0
[INFO] [stderr]    Compiling pin-project-internal v1.0.10
[INFO] [stderr]    Compiling tokio v1.17.0
[INFO] [stderr]    Compiling futures-util v0.3.21
[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 tokio-util v0.6.9
[INFO] [stderr]    Compiling futures-executor v0.3.21
[INFO] [stderr]    Compiling futures v0.3.21
[INFO] [stderr]    Compiling serde_bytes v0.11.5
[INFO] [stderr]    Compiling serde_json v1.0.79
[INFO] [stderr]    Compiling tracing-serde v0.1.3
[INFO] [stderr]    Compiling preserves v2.3.0
[INFO] [stderr]    Compiling tracing-subscriber v0.2.25
[INFO] [stderr]    Compiling preserves-schema v2.4.0
[INFO] [stderr]    Compiling syndicate v0.23.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(min_specialization)]
[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 `syndicate` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "71630b7a7a4e954fafc5d11e1970052d523452ca61bd0ddff079e8b67cd205b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "71630b7a7a4e954fafc5d11e1970052d523452ca61bd0ddff079e8b67cd205b7", kill_on_drop: false }`
[INFO] [stdout] 71630b7a7a4e954fafc5d11e1970052d523452ca61bd0ddff079e8b67cd205b7