[INFO] fetching crate byml 0.1.4...
[INFO] testing byml-0.1.4 against beta-2021-08-01 for beta-1.55-1
[INFO] extracting crate byml 0.1.4 into /workspace/builds/worker-79/source
[INFO] validating manifest of crates.io crate byml 0.1.4 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate byml 0.1.4
[INFO] finished tweaking crates.io crate byml 0.1.4
[INFO] tweaked toml for crates.io crate byml 0.1.4 written to /workspace/builds/worker-79/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "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" "+beta-2021-08-01" "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-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 42b970cf436e1566f9ad2095e4f5e461e00f1ed01f39a660863088a074b8d6aa
[INFO] running `Command { std: "docker" "start" "-a" "42b970cf436e1566f9ad2095e4f5e461e00f1ed01f39a660863088a074b8d6aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "42b970cf436e1566f9ad2095e4f5e461e00f1ed01f39a660863088a074b8d6aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42b970cf436e1566f9ad2095e4f5e461e00f1ed01f39a660863088a074b8d6aa", kill_on_drop: false }`
[INFO] [stdout] 42b970cf436e1566f9ad2095e4f5e461e00f1ed01f39a660863088a074b8d6aa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5303d65210d13b7b422652e5e38fc72aa1ce126ebad6e3a60dd04458a36feb1a
[INFO] running `Command { std: "docker" "start" "-a" "5303d65210d13b7b422652e5e38fc72aa1ce126ebad6e3a60dd04458a36feb1a", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling futures-core v0.3.16
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling futures-task v0.3.16
[INFO] [stderr]    Compiling futures-channel v0.3.16
[INFO] [stderr]    Compiling futures-sink v0.3.16
[INFO] [stderr]    Compiling strsim v0.9.3
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling slab v0.4.4
[INFO] [stderr]    Compiling pin-utils v0.1.0
[INFO] [stderr]    Compiling futures-io v0.3.16
[INFO] [stderr]    Compiling pin-project-lite v0.2.7
[INFO] [stderr]    Compiling async-trait v0.1.51
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling nodrop v0.1.14
[INFO] [stderr]    Compiling hashbrown v0.11.2
[INFO] [stderr]    Compiling once_cell v1.8.0
[INFO] [stderr]    Compiling memoffset v0.6.4
[INFO] [stderr]    Compiling futures-macro v0.3.16
[INFO] [stderr]    Compiling futures-util v0.3.16
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling indexmap v1.7.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.5
[INFO] [stderr]    Compiling async-mutex v1.4.0
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling paste-impl v0.1.18
[INFO] [stderr]    Compiling crossbeam-channel v0.5.1
[INFO] [stderr]    Compiling paste v0.1.18
[INFO] [stderr]    Compiling yaz0 v0.1.2
[INFO] [stderr]    Compiling crossbeam-deque v0.8.1
[INFO] [stderr]    Compiling parse_int v0.4.0
[INFO] [stderr]    Compiling darling_core v0.10.2
[INFO] [stderr]    Compiling binread_derive v1.4.3
[INFO] [stderr]    Compiling thiserror-impl v1.0.26
[INFO] [stderr]    Compiling binwrite_derive v0.2.1
[INFO] [stderr]    Compiling darling_macro v0.10.2
[INFO] [stderr]    Compiling binwrite v0.2.1
[INFO] [stderr]    Compiling thiserror v1.0.26
[INFO] [stderr]    Compiling darling v0.10.2
[INFO] [stderr]    Compiling cached_proc_macro v0.4.0
[INFO] [stderr]    Compiling binread v1.4.1
[INFO] [stderr]    Compiling futures-executor v0.3.16
[INFO] [stderr]    Compiling futures v0.3.16
[INFO] [stderr]    Compiling cached v0.20.0
[INFO] [stderr]    Compiling byml v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(seek_convenience)]
[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 `byml` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "5303d65210d13b7b422652e5e38fc72aa1ce126ebad6e3a60dd04458a36feb1a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5303d65210d13b7b422652e5e38fc72aa1ce126ebad6e3a60dd04458a36feb1a", kill_on_drop: false }`
[INFO] [stdout] 5303d65210d13b7b422652e5e38fc72aa1ce126ebad6e3a60dd04458a36feb1a
