[INFO] fetching crate nimiq-client 0.2.0...
[INFO] documenting nimiq-client-0.2.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate nimiq-client 0.2.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate nimiq-client 0.2.0 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nimiq-client 0.2.0
[INFO] finished tweaking crates.io crate nimiq-client 0.2.0
[INFO] tweaked toml for crates.io crate nimiq-client 0.2.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate nimiq-client 0.2.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+1.46.0" "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] 54dbba9fb1d04dfd9cd8092e7dc6320622bf21bab836f290a22016d359f06521
[INFO] running `Command { std: "docker" "start" "-a" "54dbba9fb1d04dfd9cd8092e7dc6320622bf21bab836f290a22016d359f06521", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "54dbba9fb1d04dfd9cd8092e7dc6320622bf21bab836f290a22016d359f06521", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54dbba9fb1d04dfd9cd8092e7dc6320622bf21bab836f290a22016d359f06521", kill_on_drop: false }`
[INFO] [stdout] 54dbba9fb1d04dfd9cd8092e7dc6320622bf21bab836f290a22016d359f06521
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 278bebe2a35d6cd564d539e4f1c0f10fe627a6bb69dd6feefb6025d8fa3d472b
[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" "278bebe2a35d6cd564d539e4f1c0f10fe627a6bb69dd6feefb6025d8fa3d472b", kill_on_drop: false }`
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]    Compiling subtle v2.2.1
[INFO] [stderr]     Checking constant_time_eq v0.1.4
[INFO] [stderr]     Checking nimiq-macros v0.2.0
[INFO] [stderr]     Checking data-encoding v2.1.2
[INFO] [stderr]     Checking bit-vec v0.5.1
[INFO] [stderr]     Checking nimiq-collections v0.2.0
[INFO] [stderr]    Compiling serde v1.0.102
[INFO] [stderr]     Checking remove_dir_all v0.5.2
[INFO] [stderr]     Checking atomic v0.4.5
[INFO] [stderr]     Checking supercow v0.1.0
[INFO] [stderr]     Checking utf-8 v0.7.5
[INFO] [stderr]    Compiling winapi v0.3.8
[INFO] [stderr]    Compiling cgmath v0.16.1
[INFO] [stderr]     Checking weak-table v0.2.3
[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/nimiq-collections-0.2.0/src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(box_into_raw_non_null)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/nimiq-collections-0.2.0/src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(specialization)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking rgb v0.8.14
[INFO] [stderr]     Checking json v0.11.15
[INFO] [stderr]     Checking termcolor v0.3.6
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-bigint v0.2.3
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `nimiq-collections`.
[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" "278bebe2a35d6cd564d539e4f1c0f10fe627a6bb69dd6feefb6025d8fa3d472b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "278bebe2a35d6cd564d539e4f1c0f10fe627a6bb69dd6feefb6025d8fa3d472b", kill_on_drop: false }`
[INFO] [stdout] 278bebe2a35d6cd564d539e4f1c0f10fe627a6bb69dd6feefb6025d8fa3d472b