[INFO] cloning repository https://github.com/tynr426/concurrent_prog
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tynr426/concurrent_prog" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftynr426%2Fconcurrent_prog", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftynr426%2Fconcurrent_prog'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b6ebb7610abe74273975100bb8192b92d59660e1
[INFO] testing tynr426/concurrent_prog against beta-2021-01-01 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftynr426%2Fconcurrent_prog" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tynr426/concurrent_prog 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 git repo https://github.com/tynr426/concurrent_prog
[INFO] finished tweaking git repo https://github.com/tynr426/concurrent_prog
[INFO] tweaked toml for git repo https://github.com/tynr426/concurrent_prog written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/tynr426/concurrent_prog already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+beta-2021-01-01" "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] d7e6c27b228ae745dc916fcefa85db0ff8d3bb0a6a89664ae9194f183a204d4e
[INFO] running `Command { std: "docker" "start" "-a" "d7e6c27b228ae745dc916fcefa85db0ff8d3bb0a6a89664ae9194f183a204d4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d7e6c27b228ae745dc916fcefa85db0ff8d3bb0a6a89664ae9194f183a204d4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d7e6c27b228ae745dc916fcefa85db0ff8d3bb0a6a89664ae9194f183a204d4e", kill_on_drop: false }`
[INFO] [stdout] d7e6c27b228ae745dc916fcefa85db0ff8d3bb0a6a89664ae9194f183a204d4e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5825c21a56d1e3ed52d94411210c4240e387ecc50a9e99107203915cc535bd39
[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" "5825c21a56d1e3ed52d94411210c4240e387ecc50a9e99107203915cc535bd39", kill_on_drop: false }`
[INFO] [stderr]    Compiling concurrent_prog v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0603]: function `mutex_test` is private
[INFO] [stdout]  --> src/main.rs:5:18
[INFO] [stdout]   |
[INFO] [stdout] 5 | use mutex_learn::mutex_test;
[INFO] [stdout]   |                  ^^^^^^^^^^ private function
[INFO] [stdout]   |
[INFO] [stdout] note: the function `mutex_test` is defined here
[INFO] [stdout]  --> src/mutex_learn.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn mutex_test() {
[INFO] [stdout]   | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/mutex_learn.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0603`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `concurrent_prog`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "5825c21a56d1e3ed52d94411210c4240e387ecc50a9e99107203915cc535bd39", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5825c21a56d1e3ed52d94411210c4240e387ecc50a9e99107203915cc535bd39", kill_on_drop: false }`
[INFO] [stdout] 5825c21a56d1e3ed52d94411210c4240e387ecc50a9e99107203915cc535bd39