[INFO] fetching crate bc4py-plot-cli 0.1.0...
[INFO] testing bc4py-plot-cli-0.1.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate bc4py-plot-cli 0.1.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate bc4py-plot-cli 0.1.0 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate bc4py-plot-cli 0.1.0
[INFO] finished tweaking crates.io crate bc4py-plot-cli 0.1.0
[INFO] tweaked toml for crates.io crate bc4py-plot-cli 0.1.0 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate crates.io crate bc4py-plot-cli 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 84c1d442a7773018c56974ce071f321d59b3d650e139bc84e6cde17ce27261ab
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "84c1d442a7773018c56974ce071f321d59b3d650e139bc84e6cde17ce27261ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "84c1d442a7773018c56974ce071f321d59b3d650e139bc84e6cde17ce27261ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84c1d442a7773018c56974ce071f321d59b3d650e139bc84e6cde17ce27261ab", kill_on_drop: false }`
[INFO] [stdout] 84c1d442a7773018c56974ce071f321d59b3d650e139bc84e6cde17ce27261ab
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2c794cbaa22f6b47d68d0b8029a9ff3561e68a0da118b65406d5bc11e16889a3
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "2c794cbaa22f6b47d68d0b8029a9ff3561e68a0da118b65406d5bc11e16889a3", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.71
[INFO] [stderr]    Compiling proc-macro2 v1.0.17
[INFO] [stderr]    Compiling syn v1.0.29
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling elastic-array-plus v0.10.0
[INFO] [stderr]    Compiling etcommon-hexutil v0.2.4
[INFO] [stderr]    Compiling constant_time_eq v0.1.5
[INFO] [stderr]    Compiling arrayref v0.3.6
[INFO] [stderr]    Compiling regex-syntax v0.6.18
[INFO] [stderr]    Compiling arrayvec v0.5.1
[INFO] [stderr]    Compiling strsim v0.10.0
[INFO] [stderr]    Compiling os_str_bytes v2.3.1
[INFO] [stderr]    Compiling termcolor v1.1.0
[INFO] [stderr]    Compiling proc-macro-error-attr v0.4.12
[INFO] [stderr]    Compiling proc-macro-error v0.4.12
[INFO] [stderr]    Compiling indexmap v1.3.2
[INFO] [stderr]    Compiling aho-corasick v0.7.10
[INFO] [stderr]    Compiling blake2b_simd v0.5.10
[INFO] [stderr]    Compiling etcommon-rlp v0.2.5
[INFO] [stderr]    Compiling quote v1.0.6
[INFO] [stderr]    Compiling jobserver v0.1.21
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling cc v1.0.54
[INFO] [stderr]    Compiling rand v0.3.23
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling etcommon-bigint v0.2.10
[INFO] [stderr]    Compiling bc4py_hash v0.1.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/bc4py_hash-0.1.2/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(link_args)]
[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 `bc4py_hash`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "2c794cbaa22f6b47d68d0b8029a9ff3561e68a0da118b65406d5bc11e16889a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2c794cbaa22f6b47d68d0b8029a9ff3561e68a0da118b65406d5bc11e16889a3", kill_on_drop: false }`
[INFO] [stdout] 2c794cbaa22f6b47d68d0b8029a9ff3561e68a0da118b65406d5bc11e16889a3