[INFO] fetching crate mantle-build 0.2.2...
[INFO] documenting mantle-build-0.2.2 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate mantle-build 0.2.2 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate mantle-build 0.2.2 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 mantle-build 0.2.2
[INFO] finished tweaking crates.io crate mantle-build 0.2.2
[INFO] tweaked toml for crates.io crate mantle-build 0.2.2 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate mantle-build 0.2.2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded default-env v0.1.1
[INFO] [stderr]   Downloaded mantle v0.2.0
[INFO] [stderr]   Downloaded mantle-rpc v0.1.1
[INFO] [stderr]   Downloaded blockchain-traits v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] [stdout] 155ff5ec6480134c54863c12ab5521b7da0b29fe8a5840bac3632a276341edf0
[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" "155ff5ec6480134c54863c12ab5521b7da0b29fe8a5840bac3632a276341edf0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "155ff5ec6480134c54863c12ab5521b7da0b29fe8a5840bac3632a276341edf0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "155ff5ec6480134c54863c12ab5521b7da0b29fe8a5840bac3632a276341edf0", kill_on_drop: false }`
[INFO] [stdout] 155ff5ec6480134c54863c12ab5521b7da0b29fe8a5840bac3632a276341edf0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 48847b554eb944d794fe6f0a9b8ccdcb2941aa546af7291ed8e15ee2f2cb92e3
[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" "48847b554eb944d794fe6f0a9b8ccdcb2941aa546af7291ed8e15ee2f2cb92e3", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling serde v1.0.94
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]     Checking rustc-demangle v0.1.15
[INFO] [stderr]    Compiling winapi v0.3.7
[INFO] [stderr]     Checking wasmparser v0.30.0
[INFO] [stderr]     Checking rgb v0.8.13
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking arrayvec v0.4.10
[INFO] [stderr]     Checking crossbeam-utils v0.6.5
[INFO] [stderr]     Checking heck v0.3.1
[INFO] [stderr]     Checking libflate v0.1.25
[INFO] [stderr]     Checking crossbeam-epoch v0.7.1
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking crossbeam-deque v0.6.3
[INFO] [stderr]     Checking num_cpus v1.10.1
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking rayon-core v1.5.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.30
[INFO] [stderr]     Checking rayon v1.1.0
[INFO] [stderr]     Checking cgmath v0.16.1
[INFO] [stderr]     Checking backtrace v0.3.32
[INFO] [stderr]     Checking id-arena v2.2.1
[INFO] [stderr]     Checking winconsole v0.10.0
[INFO] [stderr]     Checking colored v1.8.0
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling serde_derive v1.0.94
[INFO] [stderr]    Compiling walrus-macro v0.8.0
[INFO] [stderr]    Compiling proc-macro-hack v0.5.8
[INFO] [stderr]    Compiling proc-quote-impl v0.2.2
[INFO] [stderr]     Checking failure v0.1.5
[INFO] [stderr]     Checking proc-quote v0.2.2
[INFO] [stderr]     Checking walrus v0.8.0
[INFO] [stderr]     Checking serde_json v1.0.40
[INFO] [stderr]     Checking toml v0.5.1
[INFO] [stderr]     Checking mantle-rpc v0.1.1
[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/mantle-rpc-0.1.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(box_syntax)]
[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 `mantle-rpc`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "48847b554eb944d794fe6f0a9b8ccdcb2941aa546af7291ed8e15ee2f2cb92e3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48847b554eb944d794fe6f0a9b8ccdcb2941aa546af7291ed8e15ee2f2cb92e3", kill_on_drop: false }`
[INFO] [stdout] 48847b554eb944d794fe6f0a9b8ccdcb2941aa546af7291ed8e15ee2f2cb92e3