[INFO] fetching crate lockbook_core 3.3.6...
[INFO] testing lockbook_core-3.3.6 against 1.49.0 for beta-1.50-1
[INFO] extracting crate lockbook_core 3.3.6 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate lockbook_core 3.3.6 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 lockbook_core 3.3.6
[INFO] finished tweaking crates.io crate lockbook_core 3.3.6
[INFO] tweaked toml for crates.io crate lockbook_core 3.3.6 written to /workspace/builds/worker-10/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] 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-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] 3d8b50ce94db0f847617ffd10788d45db5fc90bf6b9cb328114221230dd13d85
[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" "3d8b50ce94db0f847617ffd10788d45db5fc90bf6b9cb328114221230dd13d85", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3d8b50ce94db0f847617ffd10788d45db5fc90bf6b9cb328114221230dd13d85", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3d8b50ce94db0f847617ffd10788d45db5fc90bf6b9cb328114221230dd13d85", kill_on_drop: false }`
[INFO] [stdout] 3d8b50ce94db0f847617ffd10788d45db5fc90bf6b9cb328114221230dd13d85
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] f59c60f12cad404a93e506ea8d25ea1be0c14aa6ee503b594cc4117782897b11
[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" "f59c60f12cad404a93e506ea8d25ea1be0c14aa6ee503b594cc4117782897b11", kill_on_drop: false }`
[INFO] [stderr]    Compiling smallvec v1.6.0
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling num-bigint-dig v0.6.1
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling fs2 v0.4.3
[INFO] [stderr]    Compiling block-cipher-trait v0.6.2
[INFO] [stderr]    Compiling universal-hash v0.3.0
[INFO] [stderr]    Compiling aead v0.2.0
[INFO] [stderr]    Compiling zeroize_derive v1.0.1
[INFO] [stderr]    Compiling aes-soft v0.3.3
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling openssl v0.10.32
[INFO] [stderr]    Compiling publicsuffix v1.5.4
[INFO] [stderr]    Compiling polyval v0.3.3
[INFO] [stderr]    Compiling parking_lot_core v0.7.2
[INFO] [stderr]    Compiling ghash v0.2.3
[INFO] [stderr]    Compiling aes v0.3.2
[INFO] [stderr]    Compiling parking_lot v0.10.2
[INFO] [stderr]    Compiling tokio-executor v0.1.10
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling crossbeam-queue v0.2.3
[INFO] [stderr]    Compiling cookie_store v0.7.0
[INFO] [stderr]    Compiling tokio-reactor v0.1.12
[INFO] [stderr]    Compiling tokio-current-thread v0.1.7
[INFO] [stderr]    Compiling tokio-timer v0.2.13
[INFO] [stderr]    Compiling crossbeam-deque v0.7.3
[INFO] [stderr]    Compiling sled v0.31.0
[INFO] [stderr]    Compiling tokio-threadpool v0.1.18
[INFO] [stderr]    Compiling tokio-tcp v0.1.4
[INFO] [stderr]    Compiling zeroize v1.2.0
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling aes-gcm v0.5.0
[INFO] [stderr]    Compiling tokio v0.1.22
[INFO] [stderr]    Compiling hyper v0.12.35
[INFO] [stderr]    Compiling native-tls v0.2.7
[INFO] [stderr]    Compiling rsa v0.2.0
[INFO] [stderr]    Compiling hyper-tls v0.3.2
[INFO] [stderr]    Compiling reqwest v0.9.24
[INFO] [stderr]    Compiling lockbook_core v3.3.6 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(try_trait)]
[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 `lockbook_core`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "f59c60f12cad404a93e506ea8d25ea1be0c14aa6ee503b594cc4117782897b11", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f59c60f12cad404a93e506ea8d25ea1be0c14aa6ee503b594cc4117782897b11", kill_on_drop: false }`
[INFO] [stdout] f59c60f12cad404a93e506ea8d25ea1be0c14aa6ee503b594cc4117782897b11