[INFO] fetching crate prng 0.1.1...
[INFO] testing prng-0.1.1 against 1.49.0 for beta-1.50-1
[INFO] extracting crate prng 0.1.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate prng 0.1.1 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 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-14/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] [stderr]     Blocking waiting for file lock on package cache
[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-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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 77afc2248cd1dd7e9a1b653f6cf05129ac5469aa4eea2470e37972f54192d4b5
[INFO] running `Command { std: "docker" "start" "-a" "77afc2248cd1dd7e9a1b653f6cf05129ac5469aa4eea2470e37972f54192d4b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "77afc2248cd1dd7e9a1b653f6cf05129ac5469aa4eea2470e37972f54192d4b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "77afc2248cd1dd7e9a1b653f6cf05129ac5469aa4eea2470e37972f54192d4b5", kill_on_drop: false }`
[INFO] [stdout] 77afc2248cd1dd7e9a1b653f6cf05129ac5469aa4eea2470e37972f54192d4b5
[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=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] 9630ac073330c96f183e5458d62d9ea87f7d89ba76f976e45225482f98076f73
[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" "9630ac073330c96f183e5458d62d9ea87f7d89ba76f976e45225482f98076f73", kill_on_drop: false }`
[INFO] [stderr]    Compiling rng_trait v0.1.1
[INFO] [stderr]    Compiling 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 stable 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] [stderr] error: could not compile `prng`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "9630ac073330c96f183e5458d62d9ea87f7d89ba76f976e45225482f98076f73", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9630ac073330c96f183e5458d62d9ea87f7d89ba76f976e45225482f98076f73", kill_on_drop: false }`
[INFO] [stdout] 9630ac073330c96f183e5458d62d9ea87f7d89ba76f976e45225482f98076f73