[INFO] cloning repository https://github.com/scan/an-os
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/scan/an-os" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscan%2Fan-os", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscan%2Fan-os'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 36b06427a706a744a45f4f7b1962a9e937ceb63d
[INFO] testing scan/an-os against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscan%2Fan-os" "/workspace/builds/worker-10/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-10/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/scan/an-os on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-10/source/.cargo/config
[INFO] started tweaking git repo https://github.com/scan/an-os
[INFO] removed 0 missing tests
[INFO] finished tweaking git repo https://github.com/scan/an-os
[INFO] tweaked toml for git repo https://github.com/scan/an-os written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate git repo https://github.com/scan/an-os already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "+1.49.0" "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] 1fa5f1fc638b26d50158e6b69a7ad860f2e28da9f489b850593fc009b948937c
[INFO] running `Command { std: "docker" "start" "-a" "1fa5f1fc638b26d50158e6b69a7ad860f2e28da9f489b850593fc009b948937c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1fa5f1fc638b26d50158e6b69a7ad860f2e28da9f489b850593fc009b948937c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1fa5f1fc638b26d50158e6b69a7ad860f2e28da9f489b850593fc009b948937c", kill_on_drop: false }`
[INFO] [stdout] 1fa5f1fc638b26d50158e6b69a7ad860f2e28da9f489b850593fc009b948937c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "+1.49.0" "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] 20fbdb5c5fa53e13b41aa98c7921ba8adc125ee8911b9eced42e5e8af8e7fcd8
[INFO] running `Command { std: "docker" "start" "-a" "20fbdb5c5fa53e13b41aa98c7921ba8adc125ee8911b9eced42e5e8af8e7fcd8", kill_on_drop: false }`
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling bit_field v0.9.0
[INFO] [stderr]    Compiling cast v0.2.2
[INFO] [stderr]    Compiling ux v0.1.3
[INFO] [stderr]    Compiling llvm-tools v0.1.1
[INFO] [stderr]    Compiling zero v0.1.2
[INFO] [stderr]    Compiling spin v0.5.2
[INFO] [stderr]    Compiling usize_conversions v0.2.0
[INFO] [stderr]    Compiling fixedvec v0.2.4
[INFO] [stderr]    Compiling spin v0.4.10
[INFO] [stderr]    Compiling volatile v0.2.6
[INFO] [stderr]    Compiling bitflags v1.1.0
[INFO] [stderr]    Compiling raw-cpuid v6.1.0
[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/usize_conversions-0.2.0/src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(i128_type)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling array-init v0.0.4
[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 `usize_conversions`
[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] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.10/src/lib.rs:6:35
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![cfg_attr(feature = "const_fn", feature(const_fn))]
[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: build failed
[INFO] running `Command { std: "docker" "inspect" "20fbdb5c5fa53e13b41aa98c7921ba8adc125ee8911b9eced42e5e8af8e7fcd8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "20fbdb5c5fa53e13b41aa98c7921ba8adc125ee8911b9eced42e5e8af8e7fcd8", kill_on_drop: false }`
[INFO] [stdout] 20fbdb5c5fa53e13b41aa98c7921ba8adc125ee8911b9eced42e5e8af8e7fcd8