[INFO] fetching crate get_env 0.1.0...
[INFO] testing get_env-0.1.0 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate get_env 0.1.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate get_env 0.1.0 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 crates.io crate get_env 0.1.0
[INFO] finished tweaking crates.io crate get_env 0.1.0
[INFO] tweaked toml for crates.io crate get_env 0.1.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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 float-cmp v0.4.0
[INFO] [stderr]   Downloaded escargot v0.2.0
[INFO] [stderr]   Downloaded predicates v0.5.2
[INFO] [stderr]   Downloaded assert_cmd v0.6.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] df368a4223476b8bf5e4cef5617d1eb3a17cbd3d90877e7a40c867c9208b2976
[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" "df368a4223476b8bf5e4cef5617d1eb3a17cbd3d90877e7a40c867c9208b2976", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "df368a4223476b8bf5e4cef5617d1eb3a17cbd3d90877e7a40c867c9208b2976", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "df368a4223476b8bf5e4cef5617d1eb3a17cbd3d90877e7a40c867c9208b2976", kill_on_drop: false }`
[INFO] [stdout] df368a4223476b8bf5e4cef5617d1eb3a17cbd3d90877e7a40c867c9208b2976
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4fa4b3f960136ec1bb27c09e22cc12373a0e535568f55934a9e8c0b05a9a64ce
[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" "4fa4b3f960136ec1bb27c09e22cc12373a0e535568f55934a9e8c0b05a9a64ce", kill_on_drop: false }`
[INFO] [stderr]    Compiling get_env v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:35:2
[INFO] [stdout]    |
[INFO] [stdout] 35 |     feature(used)
[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 `get_env`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "4fa4b3f960136ec1bb27c09e22cc12373a0e535568f55934a9e8c0b05a9a64ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4fa4b3f960136ec1bb27c09e22cc12373a0e535568f55934a9e8c0b05a9a64ce", kill_on_drop: false }`
[INFO] [stdout] 4fa4b3f960136ec1bb27c09e22cc12373a0e535568f55934a9e8c0b05a9a64ce