[INFO] fetching crate casper-engine-grpc-server 0.6.3...
[INFO] documenting casper-engine-grpc-server-0.6.3 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate casper-engine-grpc-server 0.6.3 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate casper-engine-grpc-server 0.6.3 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate casper-engine-grpc-server 0.6.3
[INFO] finished tweaking crates.io crate casper-engine-grpc-server 0.6.3
[INFO] tweaked toml for crates.io crate casper-engine-grpc-server 0.6.3 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate casper-engine-grpc-server 0.6.3 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "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] 2947a3c05d009b2d927711e244e67c26810fc0df9b82abd00ea470814295ea27
[INFO] running `Command { std: "docker" "start" "-a" "2947a3c05d009b2d927711e244e67c26810fc0df9b82abd00ea470814295ea27", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2947a3c05d009b2d927711e244e67c26810fc0df9b82abd00ea470814295ea27", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2947a3c05d009b2d927711e244e67c26810fc0df9b82abd00ea470814295ea27", kill_on_drop: false }`
[INFO] [stdout] 2947a3c05d009b2d927711e244e67c26810fc0df9b82abd00ea470814295ea27
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 56ea748d91465182c714ebfdf3281a01422ac71de0514b3be5b35dbb380eb48f
[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" "56ea748d91465182c714ebfdf3281a01422ac71de0514b3be5b35dbb380eb48f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.82
[INFO] [stderr]    Compiling serde_derive v1.0.119
[INFO] [stderr]    Compiling serde v1.0.119
[INFO] [stderr]    Compiling log v0.4.13
[INFO] [stderr]     Checking byteorder v1.4.2
[INFO] [stderr]     Checking futures v0.1.30
[INFO] [stderr]    Compiling protobuf v2.8.2
[INFO] [stderr]     Checking subtle v2.4.0
[INFO] [stderr]     Checking cpuid-bool v0.1.2
[INFO] [stderr]    Compiling serde_json v1.0.61
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]    Compiling schemars v0.8.0
[INFO] [stderr]    Compiling anyhow v1.0.38
[INFO] [stderr]    Compiling httpbis v0.7.0
[INFO] [stderr]     Checking hex v0.4.2
[INFO] [stderr]     Checking regex-syntax v0.6.22
[INFO] [stderr]     Checking base16 v0.2.1
[INFO] [stderr]     Checking hex_fmt v0.3.0
[INFO] [stderr]     Checking once_cell v1.5.2
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling indexmap v1.6.1
[INFO] [stderr]    Compiling num-rational v0.3.2
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling generic-array v0.14.4
[INFO] [stderr]    Compiling lmdb-sys v0.8.0
[INFO] [stderr]     Checking regex-automata v0.1.9
[INFO] [stderr]     Checking base64 v0.9.3
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling serde_derive_internals v0.25.0
[INFO] [stderr]    Compiling datasize_derive v0.2.3
[INFO] [stderr]    Compiling thiserror-impl v1.0.23
[INFO] [stderr]    Compiling num-derive v0.3.3
[INFO] [stderr]    Compiling tracing-attributes v0.1.11
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking uint v0.8.5
[INFO] [stderr]     Checking tokio-executor v0.1.10
[INFO] [stderr]     Checking tokio-sync v0.1.8
[INFO] [stderr]     Checking tokio-timer v0.1.2
[INFO] [stderr]     Checking tokio-timer v0.2.13
[INFO] [stderr]     Checking tokio-current-thread v0.1.7
[INFO] [stderr]     Checking digest v0.9.0
[INFO] [stderr]     Checking block-buffer v0.9.0
[INFO] [stderr]     Checking crypto-mac v0.8.0
[INFO] [stderr]    Compiling getrandom v0.2.1
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]     Checking datasize v0.2.3
[INFO] [stderr]     Checking sha2 v0.9.2
[INFO] [stderr]     Checking blake2 v0.9.1
[INFO] [stderr]    Compiling rand_core v0.6.1
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]     Checking getrandom v0.1.16
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking wait-timeout v0.2.0
[INFO] [stderr]     Checking unix_socket v0.5.0
[INFO] [stderr]     Checking time v0.1.43
[INFO] [stderr]     Checking hostname v0.3.1
[INFO] [stderr]     Checking dirs-sys v0.3.5
[INFO] [stderr]     Checking nix v0.18.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]    Compiling schemars_derive v0.8.0
[INFO] [stderr]    Compiling zeroize_derive v1.0.1
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling rand_chacha v0.3.0
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking num-integer v0.1.44
[INFO] [stderr]     Checking num-complex v0.3.1
[INFO] [stderr]     Checking lmdb v0.8.0
[INFO] [stderr]     Checking futures-cpupool v0.1.8
[INFO] [stderr]     Checking parking_lot v0.9.0
[INFO] [stderr]     Checking dirs v3.0.1
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]     Checking signature v1.2.2
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand_pcg v0.2.1
[INFO] [stderr]     Checking rand_xorshift v0.2.0
[INFO] [stderr]     Checking num-bigint v0.3.1
[INFO] [stderr]     Checking num-bigint v0.2.6
[INFO] [stderr]     Checking chrono v0.4.19
[INFO] [stderr]    Compiling rand v0.8.2
[INFO] [stderr]     Checking thiserror v1.0.23
[INFO] [stderr]     Checking tracing v0.1.22
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking num-rational v0.2.4
[INFO] [stderr]     Checking failure v0.1.8
[INFO] [stderr]     Checking zeroize v1.2.0
[INFO] [stderr]     Checking wasmi v0.6.2
[INFO] [stderr]    Compiling tempfile v3.2.0
[INFO] [stderr]     Checking elliptic-curve v0.5.0
[INFO] [stderr]     Checking curve25519-dalek v3.0.2
[INFO] [stderr]     Checking rusty-fork v0.3.0
[INFO] [stderr]     Checking ecdsa v0.7.2
[INFO] [stderr]     Checking k256 v0.4.2
[INFO] [stderr]     Checking proptest v0.10.1
[INFO] [stderr]     Checking ctrlc v3.1.7
[INFO] [stderr]    Compiling protobuf-codegen v2.8.2
[INFO] [stderr]    Compiling grpc-compiler v0.6.2
[INFO] [stderr]     Checking ed25519 v1.0.3
[INFO] [stderr]     Checking serde_bytes v0.11.5
[INFO] [stderr]     Checking bstr v0.2.14
[INFO] [stderr]     Checking hex-buffer-serde v0.2.2
[INFO] [stderr]     Checking uuid v0.8.2
[INFO] [stderr]     Checking bincode v1.3.1
[INFO] [stderr]     Checking ed25519-dalek v1.0.1
[INFO] [stderr]     Checking tokio-io v0.1.13
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking tokio-threadpool v0.1.18
[INFO] [stderr]     Checking tls-api v0.1.22
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]     Checking pwasm-utils v0.12.0
[INFO] [stderr]     Checking num v0.3.1
[INFO] [stderr]     Checking csv v1.1.5
[INFO] [stderr]     Checking tls-api-stub v0.1.22
[INFO] [stderr]     Checking tokio-codec v0.1.2
[INFO] [stderr]     Checking tokio-fs v0.1.7
[INFO] [stderr]     Checking tokio-tls-api v0.1.22
[INFO] [stderr]    Compiling protoc v2.8.2
[INFO] [stderr]    Compiling protoc-rust v2.8.2
[INFO] [stderr]     Checking tokio-reactor v0.1.12
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]    Compiling protoc-rust-grpc v0.6.2
[INFO] [stderr]     Checking tokio-udp v0.1.6
[INFO] [stderr]     Checking tokio-tcp v0.1.4
[INFO] [stderr]     Checking tokio-uds v0.2.7
[INFO] [stderr]     Checking casper-types v0.6.3
[INFO] [stderr]    Compiling casper-engine-grpc-server v0.6.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stderr]     Checking tokio-core v0.1.18
[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/casper-types-0.6.3/src/lib.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 |     feature(min_specialization, try_reserve)
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking tokio-uds v0.1.7
[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 `casper-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" "56ea748d91465182c714ebfdf3281a01422ac71de0514b3be5b35dbb380eb48f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56ea748d91465182c714ebfdf3281a01422ac71de0514b3be5b35dbb380eb48f", kill_on_drop: false }`
[INFO] [stdout] 56ea748d91465182c714ebfdf3281a01422ac71de0514b3be5b35dbb380eb48f
