[INFO] cloning repository https://github.com/zhaihj/rust-play-ground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zhaihj/rust-play-ground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzhaihj%2Frust-play-ground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzhaihj%2Frust-play-ground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7518e53f966e8c30644755ca289ee59c1d0e0a21
[INFO] checking zhaihj/rust-play-ground against master#d62d3f7fa9a91d933213cc10e20e740608983f64 for pr-77015
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzhaihj%2Frust-play-ground" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/zhaihj/rust-play-ground on toolchain d62d3f7fa9a91d933213cc10e20e740608983f64
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/zhaihj/rust-play-ground
[INFO] finished tweaking git repo https://github.com/zhaihj/rust-play-ground
[INFO] tweaked toml for git repo https://github.com/zhaihj/rust-play-ground written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate git repo https://github.com/zhaihj/rust-play-ground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2f919499af30218aaba05d2c549318739390453d34a8f4f6e51f2086a0df61d5
[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" "2f919499af30218aaba05d2c549318739390453d34a8f4f6e51f2086a0df61d5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f919499af30218aaba05d2c549318739390453d34a8f4f6e51f2086a0df61d5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f919499af30218aaba05d2c549318739390453d34a8f4f6e51f2086a0df61d5", kill_on_drop: false }`
[INFO] [stdout] 2f919499af30218aaba05d2c549318739390453d34a8f4f6e51f2086a0df61d5
[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=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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ce83abb03a7106824bd9409714caaa23ef32b27b901c61d9e567a9556efce5cf
[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" "ce83abb03a7106824bd9409714caaa23ef32b27b901c61d9e567a9556efce5cf", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.19
[INFO] [stderr]     Checking rustc-serialize v0.3.22
[INFO] [stderr]     Checking byteorder v1.0.0
[INFO] [stderr]     Checking memchr v1.0.1
[INFO] [stderr]     Checking csv v0.15.0
[INFO] [stderr]     Checking csv-read-test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]  --> src/bin/read-csv-matrix.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     f.read_to_string(&mut s);
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]   = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]  --> src/bin/read-csv-matrix.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     f.read_to_string(&mut s);
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]   = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.25s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "ce83abb03a7106824bd9409714caaa23ef32b27b901c61d9e567a9556efce5cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce83abb03a7106824bd9409714caaa23ef32b27b901c61d9e567a9556efce5cf", kill_on_drop: false }`
[INFO] [stdout] ce83abb03a7106824bd9409714caaa23ef32b27b901c61d9e567a9556efce5cf