[INFO] cloning repository https://github.com/belfz/mpsc-crypto-mining
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/belfz/mpsc-crypto-mining" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbelfz%2Fmpsc-crypto-mining", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbelfz%2Fmpsc-crypto-mining'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 893c34f913ae79e8cfff5b36fe12d1dd432ab148
[INFO] testing belfz/mpsc-crypto-mining against beta-2021-01-01 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbelfz%2Fmpsc-crypto-mining" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/belfz/mpsc-crypto-mining on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/belfz/mpsc-crypto-mining
[INFO] finished tweaking git repo https://github.com/belfz/mpsc-crypto-mining
[INFO] tweaked toml for git repo https://github.com/belfz/mpsc-crypto-mining written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/belfz/mpsc-crypto-mining already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded byte-tools v0.1.3
[INFO] [stderr]   Downloaded digest v0.4.0
[INFO] [stderr]   Downloaded generic-array v0.6.0
[INFO] [stderr]   Downloaded digest-buffer v0.2.0
[INFO] [stderr]   Downloaded nodrop v0.1.10
[INFO] [stderr]   Downloaded typenum v1.9.0
[INFO] [stderr]   Downloaded easy-hash v0.1.0
[INFO] [stderr]   Downloaded sha2 v0.4.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 34b420ab211e090e5499a8c214478d89476169108cefd7fef6683719662a8385
[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" "34b420ab211e090e5499a8c214478d89476169108cefd7fef6683719662a8385", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "34b420ab211e090e5499a8c214478d89476169108cefd7fef6683719662a8385", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34b420ab211e090e5499a8c214478d89476169108cefd7fef6683719662a8385", kill_on_drop: false }`
[INFO] [stdout] 34b420ab211e090e5499a8c214478d89476169108cefd7fef6683719662a8385
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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=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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", 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] 0c9db5aa5df41e819d9047cb6742f25e3427b2be25eff8661ba2ef0466014285
[INFO] running `Command { std: "docker" "start" "-a" "0c9db5aa5df41e819d9047cb6742f25e3427b2be25eff8661ba2ef0466014285", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.9.0
[INFO] [stderr]    Compiling odds v0.2.25
[INFO] [stderr]    Compiling byte-tools v0.1.3
[INFO] [stderr]    Compiling nodrop v0.1.10
[INFO] [stderr]    Compiling generic-array v0.6.0
[INFO] [stderr]    Compiling digest-buffer v0.2.0
[INFO] [stderr]    Compiling digest v0.4.0
[INFO] [stderr]    Compiling sha2 v0.4.2
[INFO] [stderr]    Compiling easy-hash v0.1.0
[INFO] [stderr]    Compiling mpsc-crypto-mining v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(iterator_step_by)]
[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 `mpsc-crypto-mining`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "0c9db5aa5df41e819d9047cb6742f25e3427b2be25eff8661ba2ef0466014285", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0c9db5aa5df41e819d9047cb6742f25e3427b2be25eff8661ba2ef0466014285", kill_on_drop: false }`
[INFO] [stdout] 0c9db5aa5df41e819d9047cb6742f25e3427b2be25eff8661ba2ef0466014285