[INFO] fetching crate prng 0.1.1...
[INFO] checking prng-0.1.1 against beta for pr-78714
[INFO] extracting crate prng 0.1.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate prng 0.1.1 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 prng 0.1.1
[INFO] finished tweaking crates.io crate prng 0.1.1
[INFO] tweaked toml for crates.io crate prng 0.1.1 written to /workspace/builds/worker-6/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] 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-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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6acc45510ed4dddd6d0e03844d763857b17d6de769d3c9822fdfb918957143cd
[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" "6acc45510ed4dddd6d0e03844d763857b17d6de769d3c9822fdfb918957143cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6acc45510ed4dddd6d0e03844d763857b17d6de769d3c9822fdfb918957143cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6acc45510ed4dddd6d0e03844d763857b17d6de769d3c9822fdfb918957143cd", kill_on_drop: false }`
[INFO] [stdout] 6acc45510ed4dddd6d0e03844d763857b17d6de769d3c9822fdfb918957143cd
[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=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] 74a82a9025eb4e013cfb8f298e18e19321e287db49b89f14497b2e964dfa7053
[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" "74a82a9025eb4e013cfb8f298e18e19321e287db49b89f14497b2e964dfa7053", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking rng_trait v0.1.1
[INFO] [stderr]     Checking prng v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `alloc::arc`
[INFO] [stdout]  --> src/atomic_prng.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use alloc::arc::Arc;
[INFO] [stdout]   |            ^^^ could not find `arc` in `alloc`
[INFO] [stdout] 
[INFO] [stdout] 
[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(alloc)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `alloc::arc`
[INFO] [stdout]  --> src/atomic_prng.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use alloc::arc::Arc;
[INFO] [stdout]   |            ^^^ could not find `arc` in `alloc`
[INFO] [stdout] 
[INFO] [stdout] 
[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(alloc)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `prng`
[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] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "74a82a9025eb4e013cfb8f298e18e19321e287db49b89f14497b2e964dfa7053", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "74a82a9025eb4e013cfb8f298e18e19321e287db49b89f14497b2e964dfa7053", kill_on_drop: false }`
[INFO] [stdout] 74a82a9025eb4e013cfb8f298e18e19321e287db49b89f14497b2e964dfa7053