[INFO] cloning repository https://github.com/dagit/emu-test
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dagit/emu-test" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdagit%2Femu-test", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdagit%2Femu-test'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f019c9551ff008e79e619f3c7fbd81da3823fbf6
[INFO] testing dagit/emu-test 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%2Fdagit%2Femu-test" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dagit/emu-test 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/dagit/emu-test
[INFO] finished tweaking git repo https://github.com/dagit/emu-test
[INFO] tweaked toml for git repo https://github.com/dagit/emu-test written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/dagit/emu-test 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]  Downloading crates ...
[INFO] [stderr]   Downloaded genawaiter-macro v0.99.1
[INFO] [stderr]   Downloaded genawaiter-proc-macro v0.99.1
[INFO] [stderr]   Downloaded genawaiter v0.99.1
[INFO] [stderr]   Downloaded tokio v0.2.19
[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" "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] f10f86bfbaf05d64cb82dea531b627c36d3b527884f42c38df1f4f7c84a46fef
[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" "f10f86bfbaf05d64cb82dea531b627c36d3b527884f42c38df1f4f7c84a46fef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f10f86bfbaf05d64cb82dea531b627c36d3b527884f42c38df1f4f7c84a46fef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f10f86bfbaf05d64cb82dea531b627c36d3b527884f42c38df1f4f7c84a46fef", kill_on_drop: false }`
[INFO] [stdout] f10f86bfbaf05d64cb82dea531b627c36d3b527884f42c38df1f4f7c84a46fef
[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" "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] 51d179f1401656bfe95ff0c9a6d65e50f3e7205973a3d1ba88878dddb741f66a
[INFO] running `Command { std: "docker" "start" "-a" "51d179f1401656bfe95ff0c9a6d65e50f3e7205973a3d1ba88878dddb741f66a", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling genawaiter-macro v0.99.1
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling crossbeam-channel v0.4.2
[INFO] [stderr]    Compiling crossbeam-deque v0.7.3
[INFO] [stderr]    Compiling async-std v1.5.0
[INFO] [stderr]    Compiling syn-mid v0.5.0
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]    Compiling proc-macro-error-attr v0.4.12
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]    Compiling proc-macro-error v0.4.12
[INFO] [stderr]    Compiling tokio v0.2.19
[INFO] [stderr]    Compiling futures-util v0.3.4
[INFO] [stderr]    Compiling genawaiter-proc-macro v0.99.1
[INFO] [stderr]    Compiling genawaiter v0.99.1
[INFO] [stderr]    Compiling futures-executor v0.3.4
[INFO] [stderr]    Compiling futures v0.3.4
[INFO] [stderr]    Compiling emu-test 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(generators, generator_trait)]
[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 `emu-test`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "51d179f1401656bfe95ff0c9a6d65e50f3e7205973a3d1ba88878dddb741f66a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "51d179f1401656bfe95ff0c9a6d65e50f3e7205973a3d1ba88878dddb741f66a", kill_on_drop: false }`
[INFO] [stdout] 51d179f1401656bfe95ff0c9a6d65e50f3e7205973a3d1ba88878dddb741f66a