[INFO] updating cached repository https://github.com/HsiangSun/rust_study
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cafc19252292e98dc652fbf9ef9a99bf8a5f4cea
[INFO] testing HsiangSun/rust_study against beta-2020-07-24 for beta-1.46-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHsiangSun%2Frust_study" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/HsiangSun/rust_study on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/HsiangSun/rust_study
[INFO] finished tweaking git repo https://github.com/HsiangSun/rust_study
[INFO] tweaked toml for git repo https://github.com/HsiangSun/rust_study written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/HsiangSun/rust_study already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bfaf3bec2ae653f284a5f6d7bd557b226e1381cf994e8092eeef4d9043ff346b
[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" "bfaf3bec2ae653f284a5f6d7bd557b226e1381cf994e8092eeef4d9043ff346b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bfaf3bec2ae653f284a5f6d7bd557b226e1381cf994e8092eeef4d9043ff346b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bfaf3bec2ae653f284a5f6d7bd557b226e1381cf994e8092eeef4d9043ff346b", kill_on_drop: false }`
[INFO] [stdout] bfaf3bec2ae653f284a5f6d7bd557b226e1381cf994e8092eeef4d9043ff346b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8152cd5371034ddb82adb705df847f8b3c55095f801349948ceaa9d0deb71f9b
[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" "8152cd5371034ddb82adb705df847f8b3c55095f801349948ceaa9d0deb71f9b", kill_on_drop: false }`
[INFO] [stderr]    Compiling study01 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/io.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let f = File::create("./rust.txt").unwrap();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.95s
[INFO] running `Command { std: "docker" "inspect" "8152cd5371034ddb82adb705df847f8b3c55095f801349948ceaa9d0deb71f9b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8152cd5371034ddb82adb705df847f8b3c55095f801349948ceaa9d0deb71f9b", kill_on_drop: false }`
[INFO] [stdout] 8152cd5371034ddb82adb705df847f8b3c55095f801349948ceaa9d0deb71f9b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 60641455853c279a54c58d3aca78d90eaad6cbf594914ee53a10a00cc8684bf3
[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" "60641455853c279a54c58d3aca78d90eaad6cbf594914ee53a10a00cc8684bf3", kill_on_drop: false }`
[INFO] [stderr]    Compiling study01 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/io.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let f = File::create("./rust.txt").unwrap();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.89s
[INFO] running `Command { std: "docker" "inspect" "60641455853c279a54c58d3aca78d90eaad6cbf594914ee53a10a00cc8684bf3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60641455853c279a54c58d3aca78d90eaad6cbf594914ee53a10a00cc8684bf3", kill_on_drop: false }`
[INFO] [stdout] 60641455853c279a54c58d3aca78d90eaad6cbf594914ee53a10a00cc8684bf3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] f91ffaccc77b5526cd75dfc43046f3bf028a668ebce0fc951ee37733fe596fc6
[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" "f91ffaccc77b5526cd75dfc43046f3bf028a668ebce0fc951ee37733fe596fc6", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]  --> src/io.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let f = File::create("./rust.txt").unwrap();
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/study01-ef78003b9d4c0d5c
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test io::unit_test ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "f91ffaccc77b5526cd75dfc43046f3bf028a668ebce0fc951ee37733fe596fc6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f91ffaccc77b5526cd75dfc43046f3bf028a668ebce0fc951ee37733fe596fc6", kill_on_drop: false }`
[INFO] [stdout] f91ffaccc77b5526cd75dfc43046f3bf028a668ebce0fc951ee37733fe596fc6