[INFO] fetching crate opencontainers 0.0.0-alpha.2...
[INFO] testing opencontainers-0.0.0-alpha.2 against 1.49.0 for beta-1.50-1
[INFO] extracting crate opencontainers 0.0.0-alpha.2 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate opencontainers 0.0.0-alpha.2 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 crates.io crate opencontainers 0.0.0-alpha.2
[INFO] finished tweaking crates.io crate opencontainers 0.0.0-alpha.2
[INFO] tweaked toml for crates.io crate opencontainers 0.0.0-alpha.2 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] 9e7c75bcfc7714101c86508cb4064be898e24809502ed9f401b24e706b574797
[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" "9e7c75bcfc7714101c86508cb4064be898e24809502ed9f401b24e706b574797", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9e7c75bcfc7714101c86508cb4064be898e24809502ed9f401b24e706b574797", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9e7c75bcfc7714101c86508cb4064be898e24809502ed9f401b24e706b574797", kill_on_drop: false }`
[INFO] [stdout] 9e7c75bcfc7714101c86508cb4064be898e24809502ed9f401b24e706b574797
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] b7bb6566546776a70fa9f77518518281c143cfbf9148e90915db267df767038e
[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" "b7bb6566546776a70fa9f77518518281c143cfbf9148e90915db267df767038e", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling ucd-trie v0.1.3
[INFO] [stderr]    Compiling maplit v1.0.2
[INFO] [stderr]    Compiling linked-hash-map v0.5.3
[INFO] [stderr]    Compiling want v0.2.0
[INFO] [stderr]    Compiling mio v0.6.23
[INFO] [stderr]    Compiling tokio-io v0.1.13
[INFO] [stderr]    Compiling hyperx v0.13.2
[INFO] [stderr]    Compiling tokio-threadpool v0.1.18
[INFO] [stderr]    Compiling native-tls v0.2.7
[INFO] [stderr]    Compiling publicsuffix v1.5.4
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling pest v2.1.3
[INFO] [stderr]    Compiling ttl_cache v0.5.1
[INFO] [stderr]    Compiling unicase v1.4.2
[INFO] [stderr]    Compiling h2 v0.1.26
[INFO] [stderr]    Compiling cookie_store v0.7.0
[INFO] [stderr]    Compiling tokio-reactor v0.1.12
[INFO] [stderr]    Compiling tokio-tcp v0.1.4
[INFO] [stderr]    Compiling www-authenticate v0.3.0
[INFO] [stderr]    Compiling tokio v0.1.22
[INFO] [stderr]    Compiling pest_meta v2.1.3
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]    Compiling hyper v0.12.35
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]    Compiling hyper-tls v0.3.2
[INFO] [stderr]    Compiling reqwest v0.9.24
[INFO] [stderr]    Compiling opencontainers v0.0.0-alpha.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(never_type)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `opencontainers`
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[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" "b7bb6566546776a70fa9f77518518281c143cfbf9148e90915db267df767038e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b7bb6566546776a70fa9f77518518281c143cfbf9148e90915db267df767038e", kill_on_drop: false }`
[INFO] [stdout] b7bb6566546776a70fa9f77518518281c143cfbf9148e90915db267df767038e