[INFO] fetching crate casperlabs-engine-wasm-prep 0.6.1...
[INFO] documenting casperlabs-engine-wasm-prep-0.6.1 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate casperlabs-engine-wasm-prep 0.6.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate casperlabs-engine-wasm-prep 0.6.1 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate casperlabs-engine-wasm-prep 0.6.1
[INFO] finished tweaking crates.io crate casperlabs-engine-wasm-prep 0.6.1
[INFO] tweaked toml for crates.io crate casperlabs-engine-wasm-prep 0.6.1 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "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] a5904e5cb2f9bc132921e33cf52eed04c8eaec234d177bb12f3d7f4d415687b7
[INFO] running `Command { std: "docker" "start" "-a" "a5904e5cb2f9bc132921e33cf52eed04c8eaec234d177bb12f3d7f4d415687b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a5904e5cb2f9bc132921e33cf52eed04c8eaec234d177bb12f3d7f4d415687b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a5904e5cb2f9bc132921e33cf52eed04c8eaec234d177bb12f3d7f4d415687b7", kill_on_drop: false }`
[INFO] [stdout] a5904e5cb2f9bc132921e33cf52eed04c8eaec234d177bb12f3d7f4d415687b7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "RUSTDOCFLAGS=--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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ac6ff7a5b32d039a50c2a2dffd0fdae8cad8a4c088553f9d75d6a9e16e80098f
[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" "ac6ff7a5b32d039a50c2a2dffd0fdae8cad8a4c088553f9d75d6a9e16e80098f", 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]     Checking rustc-hex v2.1.0
[INFO] [stderr]     Checking base16 v0.2.1
[INFO] [stderr]     Checking parity-wasm v0.41.0
[INFO] [stderr]     Checking hex_fmt v0.3.0
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking wait-timeout v0.2.0
[INFO] [stderr]     Checking num-integer v0.1.43
[INFO] [stderr]    Compiling num-derive v0.3.2
[INFO] [stderr]     Checking failure v0.1.8
[INFO] [stderr]     Checking digest v0.8.1
[INFO] [stderr]     Checking blake2 v0.8.1
[INFO] [stderr]     Checking rusty-fork v0.2.2
[INFO] [stderr]     Checking uint v0.8.5
[INFO] [stderr]     Checking proptest v0.9.6
[INFO] [stderr]     Checking pwasm-utils v0.12.0
[INFO] [stderr]     Checking casperlabs-types v0.6.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/casperlabs-types-0.6.1/src/lib.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 |     feature(min_specialization, try_reserve)
[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 `casperlabs-types`.
[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" "ac6ff7a5b32d039a50c2a2dffd0fdae8cad8a4c088553f9d75d6a9e16e80098f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac6ff7a5b32d039a50c2a2dffd0fdae8cad8a4c088553f9d75d6a9e16e80098f", kill_on_drop: false }`
[INFO] [stdout] ac6ff7a5b32d039a50c2a2dffd0fdae8cad8a4c088553f9d75d6a9e16e80098f