[INFO] cloning repository https://github.com/sumeet/aoc2019
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sumeet/aoc2019" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsumeet%2Faoc2019", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsumeet%2Faoc2019'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7e4bafbe7d05b46f466c9eb23c4da93210dfb1f0
[INFO] testing sumeet/aoc2019 against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsumeet%2Faoc2019" "/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/sumeet/aoc2019 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] started tweaking git repo https://github.com/sumeet/aoc2019
[INFO] finished tweaking git repo https://github.com/sumeet/aoc2019
[INFO] tweaked toml for git repo https://github.com/sumeet/aoc2019 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/sumeet/aoc2019 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] [stderr]     Blocking waiting for file lock on package cache
[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" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5657b83110b867fcb17c65348beacd0185cc237d68b71ccee643cedc114bd154
[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" "5657b83110b867fcb17c65348beacd0185cc237d68b71ccee643cedc114bd154", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5657b83110b867fcb17c65348beacd0185cc237d68b71ccee643cedc114bd154", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5657b83110b867fcb17c65348beacd0185cc237d68b71ccee643cedc114bd154", kill_on_drop: false }`
[INFO] [stdout] 5657b83110b867fcb17c65348beacd0185cc237d68b71ccee643cedc114bd154
[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" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c26c5436530ed0d04f30c75b685677e2d2a476d68ac15831ef0bf7371b14f9d8
[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" "c26c5436530ed0d04f30c75b685677e2d2a476d68ac15831ef0bf7371b14f9d8", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.11
[INFO] [stderr]    Compiling serde v1.0.103
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling fixedbitset v0.2.0
[INFO] [stderr]    Compiling aoc-runner v0.2.2
[INFO] [stderr]    Compiling defaultmap v0.4.0
[INFO] [stderr]    Compiling gen-iter v0.2.0
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-bigint v0.2.3
[INFO] [stderr]    Compiling num-rational v0.2.2
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling indexmap v1.3.0
[INFO] [stderr]    Compiling crossbeam-channel v0.4.0
[INFO] [stderr]    Compiling float-cmp v0.6.0
[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/gen-iter-0.2.0/src/lib.rs:33:1
[INFO] [stdout]    |
[INFO] [stdout] 33 | #![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 `gen-iter`
[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" "c26c5436530ed0d04f30c75b685677e2d2a476d68ac15831ef0bf7371b14f9d8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c26c5436530ed0d04f30c75b685677e2d2a476d68ac15831ef0bf7371b14f9d8", kill_on_drop: false }`
[INFO] [stdout] c26c5436530ed0d04f30c75b685677e2d2a476d68ac15831ef0bf7371b14f9d8