[INFO] fetching crate mantle-build 0.2.2...
[INFO] checking mantle-build-0.2.2 against beta for pr-78714
[INFO] extracting crate mantle-build 0.2.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate mantle-build 0.2.2 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "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-0/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" "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" "+beta" "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] bbda07df421a4e9ef9927a721c7ff853922e3830cf54c29268d82f2a14f5b7bf
[INFO] running `Command { std: "docker" "start" "-a" "bbda07df421a4e9ef9927a721c7ff853922e3830cf54c29268d82f2a14f5b7bf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bbda07df421a4e9ef9927a721c7ff853922e3830cf54c29268d82f2a14f5b7bf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bbda07df421a4e9ef9927a721c7ff853922e3830cf54c29268d82f2a14f5b7bf", kill_on_drop: false }`
[INFO] [stdout] bbda07df421a4e9ef9927a721c7ff853922e3830cf54c29268d82f2a14f5b7bf
[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" "RUSTFLAGS=--cap-lints=forbid" "-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" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b9e802728b682337bfd10a98e7f8b4f856afc7b682c039af4eeeebeefcc63798
[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" "b9e802728b682337bfd10a98e7f8b4f856afc7b682c039af4eeeebeefcc63798", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]     Checking spin v0.5.0
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling serde v1.0.94
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling arrayvec v0.4.10
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]     Checking nodrop v0.1.13
[INFO] [stderr]     Checking memoffset v0.2.1
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]     Checking rustc-demangle v0.1.15
[INFO] [stderr]    Compiling rayon-core v1.5.0
[INFO] [stderr]    Compiling ryu v1.0.0
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]    Compiling cgmath v0.16.1
[INFO] [stderr]    Compiling winapi v0.3.7
[INFO] [stderr]     Checking itoa v0.4.4
[INFO] [stderr]     Checking either v1.5.2
[INFO] [stderr]     Checking ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]     Checking wasmparser v0.30.0
[INFO] [stderr]     Checking adler32 v1.0.3
[INFO] [stderr]     Checking rgb v0.8.13
[INFO] [stderr]     Checking take_mut v0.2.2
[INFO] [stderr]     Checking rle-decode-fast v1.0.1
[INFO] [stderr]    Compiling regex v1.1.8
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]     Checking unicode-segmentation v1.3.0
[INFO] [stderr]     Checking utf8-ranges v1.0.3
[INFO] [stderr]     Checking half v1.3.0
[INFO] [stderr]    Compiling compiletest_rs v0.3.22
[INFO] [stderr]     Checking unicode-width v0.1.5
[INFO] [stderr]     Checking blockchain-traits v0.2.0
[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/blockchain-traits-0.2.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(non_exhaustive)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking diff v0.1.11
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking lazy_static v1.3.0
[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 `blockchain-traits`
[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" "b9e802728b682337bfd10a98e7f8b4f856afc7b682c039af4eeeebeefcc63798", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b9e802728b682337bfd10a98e7f8b4f856afc7b682c039af4eeeebeefcc63798", kill_on_drop: false }`
[INFO] [stdout] b9e802728b682337bfd10a98e7f8b4f856afc7b682c039af4eeeebeefcc63798