[INFO] fetching crate cargo-name 1.0.1...
[INFO] testing cargo-name-1.0.1 against 1.49.0 for beta-1.50-1
[INFO] extracting crate cargo-name 1.0.1 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate cargo-name 1.0.1 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 cargo-name 1.0.1
[INFO] finished tweaking crates.io crate cargo-name 1.0.1
[INFO] tweaked toml for crates.io crate cargo-name 1.0.1 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "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" "+1.49.0" "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-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 59f4e5e5a01670111bde4c946acc59ed23e120ba2c6144e9dbac536740fb3cba
[INFO] running `Command { std: "docker" "start" "-a" "59f4e5e5a01670111bde4c946acc59ed23e120ba2c6144e9dbac536740fb3cba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "59f4e5e5a01670111bde4c946acc59ed23e120ba2c6144e9dbac536740fb3cba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "59f4e5e5a01670111bde4c946acc59ed23e120ba2c6144e9dbac536740fb3cba", kill_on_drop: false }`
[INFO] [stdout] 59f4e5e5a01670111bde4c946acc59ed23e120ba2c6144e9dbac536740fb3cba
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 643b2c5c76e29c030ba029cf65b8c1e0a3c1a7bdad8cb9cc95e4ef28ccd47c1a
[INFO] running `Command { std: "docker" "start" "-a" "643b2c5c76e29c030ba029cf65b8c1e0a3c1a7bdad8cb9cc95e4ef28ccd47c1a", kill_on_drop: false }`
[INFO] [stderr]    Compiling want v0.2.0
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling mio v0.6.23
[INFO] [stderr]    Compiling futures-cpupool v0.1.8
[INFO] [stderr]    Compiling flate2 v1.0.19
[INFO] [stderr]    Compiling openssl v0.10.32
[INFO] [stderr]    Compiling tokio-threadpool v0.1.18
[INFO] [stderr]    Compiling env_logger v0.5.13
[INFO] [stderr]    Compiling cookie v0.12.0
[INFO] [stderr]    Compiling serde_urlencoded v0.5.5
[INFO] [stderr]    Compiling rayon v1.5.0
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling cookie_store v0.7.0
[INFO] [stderr]    Compiling clap-verbosity-flag v0.1.0
[INFO] [stderr]    Compiling tokio-io v0.1.13
[INFO] [stderr]    Compiling http v0.1.21
[INFO] [stderr]    Compiling tokio-buf v0.1.1
[INFO] [stderr]    Compiling string v0.2.1
[INFO] [stderr]    Compiling tokio-reactor v0.1.12
[INFO] [stderr]    Compiling uuid v0.7.4
[INFO] [stderr]    Compiling tokio-tcp v0.1.4
[INFO] [stderr]    Compiling tokio v0.1.22
[INFO] [stderr]    Compiling native-tls v0.2.7
[INFO] [stderr]    Compiling quicli v0.3.1
[INFO] [stderr]    Compiling h2 v0.1.26
[INFO] [stderr]    Compiling http-body v0.1.0
[INFO] [stderr]    Compiling hyper v0.12.35
[INFO] [stderr]    Compiling hyper-tls v0.3.2
[INFO] [stderr]    Compiling reqwest v0.9.24
[INFO] [stderr]    Compiling cargo-name v1.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(external_doc)]
[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 `cargo-name`
[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" "643b2c5c76e29c030ba029cf65b8c1e0a3c1a7bdad8cb9cc95e4ef28ccd47c1a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "643b2c5c76e29c030ba029cf65b8c1e0a3c1a7bdad8cb9cc95e4ef28ccd47c1a", kill_on_drop: false }`
[INFO] [stdout] 643b2c5c76e29c030ba029cf65b8c1e0a3c1a7bdad8cb9cc95e4ef28ccd47c1a