[INFO] fetching crate netapp 0.1.0...
[INFO] testing netapp-0.1.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate netapp 0.1.0 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate netapp 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 netapp 0.1.0
[INFO] finished tweaking crates.io crate netapp 0.1.0
[INFO] tweaked toml for crates.io crate netapp 0.1.0 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] crate crates.io crate netapp 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] 24374d4b904717c5a7e86fe313fc678a4f6006396cd2da54890e8ed01b89e730
[INFO] running `Command { std: "docker" "start" "-a" "24374d4b904717c5a7e86fe313fc678a4f6006396cd2da54890e8ed01b89e730", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "24374d4b904717c5a7e86fe313fc678a4f6006396cd2da54890e8ed01b89e730", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "24374d4b904717c5a7e86fe313fc678a4f6006396cd2da54890e8ed01b89e730", kill_on_drop: false }`
[INFO] [stdout] 24374d4b904717c5a7e86fe313fc678a4f6006396cd2da54890e8ed01b89e730
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] 8a083c83d313185a5039f8dab88d1f725549668c0929c767d1dd3ca3b7d9c54d
[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" "8a083c83d313185a5039f8dab88d1f725549668c0929c767d1dd3ca3b7d9c54d", kill_on_drop: false }`
[INFO] [stderr]    Compiling cc v1.0.65
[INFO] [stderr]    Compiling arc-swap v1.1.0
[INFO] [stderr]    Compiling futures-channel v0.3.8
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling nb-connect v1.0.2
[INFO] [stderr]    Compiling rand v0.5.6
[INFO] [stderr]    Compiling polling v2.0.2
[INFO] [stderr]    Compiling mio v0.6.23
[INFO] [stderr]    Compiling async-attributes v1.1.1
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling env_logger v0.8.2
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling rmp-serde v0.14.4
[INFO] [stderr]    Compiling async-io v1.3.1
[INFO] [stderr]    Compiling futures-util v0.3.8
[INFO] [stderr]    Compiling lru v0.6.1
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]    Compiling libsodium-sys v0.2.6
[INFO] [stderr]    Compiling async-global-executor v1.4.3
[INFO] [stderr]    Compiling mio-uds v0.6.8
[INFO] [stderr]    Compiling err-derive v0.2.4
[INFO] [stderr]    Compiling tokio v0.2.23
[INFO] [stderr]    Compiling async-std v1.7.0
[INFO] [stderr]    Compiling structopt v0.3.21
[INFO] [stderr]    Compiling futures-executor v0.3.8
[INFO] [stderr]    Compiling futures v0.3.8
[INFO] [stderr]    Compiling kuska-sodiumoxide v0.2.5-0
[INFO] [stderr]    Compiling kuska-handshake v0.1.2
[INFO] [stderr]    Compiling netapp v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:16:1
[INFO] [stdout]    |
[INFO] [stdout] 16 | #![feature(map_first_last)]
[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 `netapp`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "8a083c83d313185a5039f8dab88d1f725549668c0929c767d1dd3ca3b7d9c54d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8a083c83d313185a5039f8dab88d1f725549668c0929c767d1dd3ca3b7d9c54d", kill_on_drop: false }`
[INFO] [stdout] 8a083c83d313185a5039f8dab88d1f725549668c0929c767d1dd3ca3b7d9c54d