[INFO] fetching crate box-error 0.0.1...
[INFO] checking box-error-0.0.1 against beta for pr-78714
[INFO] extracting crate box-error 0.0.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate box-error 0.0.1 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate box-error 0.0.1
[INFO] finished tweaking crates.io crate box-error 0.0.1
[INFO] tweaked toml for crates.io crate box-error 0.0.1 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9471a271bfadfc237f23dcf7fa496e2ae73baebc7199a9156b574e64434106d4
[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" "9471a271bfadfc237f23dcf7fa496e2ae73baebc7199a9156b574e64434106d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9471a271bfadfc237f23dcf7fa496e2ae73baebc7199a9156b574e64434106d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9471a271bfadfc237f23dcf7fa496e2ae73baebc7199a9156b574e64434106d4", kill_on_drop: false }`
[INFO] [stdout] 9471a271bfadfc237f23dcf7fa496e2ae73baebc7199a9156b574e64434106d4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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=forbid" "-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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0901ec63a4116bd66a9e6218661d436a7b2852de623a899a86b33c518f65fffb
[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" "0901ec63a4116bd66a9e6218661d436a7b2852de623a899a86b33c518f65fffb", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.48
[INFO] [stderr]     Checking box-error v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(try_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fmt`
[INFO] [stdout]  --> src/lib.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::fmt;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]  --> src/lib.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::mem;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::ops::Try`
[INFO] [stdout]  --> src/lib.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::ops::Try;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]  --> src/lib.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::error::Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `box-error`
[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" "0901ec63a4116bd66a9e6218661d436a7b2852de623a899a86b33c518f65fffb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0901ec63a4116bd66a9e6218661d436a7b2852de623a899a86b33c518f65fffb", kill_on_drop: false }`
[INFO] [stdout] 0901ec63a4116bd66a9e6218661d436a7b2852de623a899a86b33c518f65fffb