[INFO] cloning repository https://github.com/munderseth/rust.sandbox
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/munderseth/rust.sandbox" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmunderseth%2Frust.sandbox", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmunderseth%2Frust.sandbox'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 00057292d3f5bcd0a5110c1153049f873052c71d
[INFO] checking munderseth/rust.sandbox against master#ecb170afc878648c3ae355dbd596c8e4b6f7ebdc for pr-139022
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmunderseth%2Frust.sandbox" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/munderseth/rust.sandbox on toolchain ecb170afc878648c3ae355dbd596c8e4b6f7ebdc
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ecb170afc878648c3ae355dbd596c8e4b6f7ebdc" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/munderseth/rust.sandbox
[INFO] finished tweaking git repo https://github.com/munderseth/rust.sandbox
[INFO] tweaked toml for git repo https://github.com/munderseth/rust.sandbox written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/munderseth/rust.sandbox already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ecb170afc878648c3ae355dbd596c8e4b6f7ebdc" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+ecb170afc878648c3ae355dbd596c8e4b6f7ebdc" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b2f55afe17ad47ead342f859cb19fa7a7d9cc6f7f46368ecd0f4b91f2fdd66ba
[INFO] running `Command { std: "docker" "start" "-a" "b2f55afe17ad47ead342f859cb19fa7a7d9cc6f7f46368ecd0f4b91f2fdd66ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b2f55afe17ad47ead342f859cb19fa7a7d9cc6f7f46368ecd0f4b91f2fdd66ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2f55afe17ad47ead342f859cb19fa7a7d9cc6f7f46368ecd0f4b91f2fdd66ba", kill_on_drop: false }`
[INFO] [stdout] b2f55afe17ad47ead342f859cb19fa7a7d9cc6f7f46368ecd0f4b91f2fdd66ba
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+ecb170afc878648c3ae355dbd596c8e4b6f7ebdc" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b91282665f488b0baa9ca91c40e9e5d6e3ec84793119e8140ac73813d5877344
[INFO] running `Command { std: "docker" "start" "-a" "b91282665f488b0baa9ca91c40e9e5d6e3ec84793119e8140ac73813d5877344", kill_on_drop: false }`
[INFO] [stderr]     Checking hello-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `from` that must be used
[INFO] [stdout]  --> src/lib.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     String::from("Hello!");
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let _ = String::from("Hello!");
[INFO] [stdout]   |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `from` that must be used
[INFO] [stdout]  --> src/lib.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     String::from("Hello!");
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let _ = String::from("Hello!");
[INFO] [stdout]   |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.51s
[INFO] running `Command { std: "docker" "inspect" "b91282665f488b0baa9ca91c40e9e5d6e3ec84793119e8140ac73813d5877344", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b91282665f488b0baa9ca91c40e9e5d6e3ec84793119e8140ac73813d5877344", kill_on_drop: false }`
[INFO] [stdout] b91282665f488b0baa9ca91c40e9e5d6e3ec84793119e8140ac73813d5877344