[INFO] fetching crate para 0.2.0...
[INFO] testing para-0.2.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate para 0.2.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate para 0.2.0 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 para 0.2.0
[INFO] finished tweaking crates.io crate para 0.2.0
[INFO] tweaked toml for crates.io crate para 0.2.0 written to /workspace/builds/worker-12/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-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] 0979cd2290e8d0e42a81f951e860adaea97decd0516a3135f4ca185884f066fb
[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" "0979cd2290e8d0e42a81f951e860adaea97decd0516a3135f4ca185884f066fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0979cd2290e8d0e42a81f951e860adaea97decd0516a3135f4ca185884f066fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0979cd2290e8d0e42a81f951e860adaea97decd0516a3135f4ca185884f066fb", kill_on_drop: false }`
[INFO] [stdout] 0979cd2290e8d0e42a81f951e860adaea97decd0516a3135f4ca185884f066fb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] d7f221a3b150357f2ef1ea5a551fc83a1fac93546a5071eb1bc7df0e12ab3fc8
[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" "d7f221a3b150357f2ef1ea5a551fc83a1fac93546a5071eb1bc7df0e12ab3fc8", kill_on_drop: false }`
[INFO] [stderr]    Compiling rich-phantoms v0.1.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.1
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.1
[INFO] [stderr]    Compiling crossbeam-channel v0.5.0
[INFO] [stderr]    Compiling crossbeam-queue v0.3.1
[INFO] [stderr]    Compiling crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling crossbeam v0.8.0
[INFO] [stderr]    Compiling para v0.2.0 (/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(in_band_lifetimes)]
[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 `para`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "d7f221a3b150357f2ef1ea5a551fc83a1fac93546a5071eb1bc7df0e12ab3fc8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d7f221a3b150357f2ef1ea5a551fc83a1fac93546a5071eb1bc7df0e12ab3fc8", kill_on_drop: false }`
[INFO] [stdout] d7f221a3b150357f2ef1ea5a551fc83a1fac93546a5071eb1bc7df0e12ab3fc8