[INFO] updating cached repository https://github.com/panta82/rust-playground
[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] 78fa006aefc08630bdd2af66ca81fff556f107fd
[INFO] checking panta82/rust-playground against master#1557fb031b272b4c5bfcc7de5df7eddc7b36a584 for pr-73166
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpanta82%2Frust-playground" "/workspace/builds/worker-10/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-10/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/panta82/rust-playground on toolchain 1557fb031b272b4c5bfcc7de5df7eddc7b36a584
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/panta82/rust-playground
[INFO] finished tweaking git repo https://github.com/panta82/rust-playground
[INFO] tweaked toml for git repo https://github.com/panta82/rust-playground written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate git repo https://github.com/panta82/rust-playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1c03100a3fcde0aa400e4cf0974821c53663aef75ef22ff6857e04ef69f6f4a5
[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" "1c03100a3fcde0aa400e4cf0974821c53663aef75ef22ff6857e04ef69f6f4a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c03100a3fcde0aa400e4cf0974821c53663aef75ef22ff6857e04ef69f6f4a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c03100a3fcde0aa400e4cf0974821c53663aef75ef22ff6857e04ef69f6f4a5", kill_on_drop: false }`
[INFO] [stdout] 1c03100a3fcde0aa400e4cf0974821c53663aef75ef22ff6857e04ef69f6f4a5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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=forbid" "-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" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5c8ceed64e0470ba093c91a4a4f568d4a1bf802ca3e959613823a8cbf17b2ac7
[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" "5c8ceed64e0470ba093c91a4a4f568d4a1bf802ca3e959613823a8cbf17b2ac7", kill_on_drop: false }`
[INFO] [stderr]     Checking hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function is never used: `read_to_string_v1`
[INFO] [stdout]   --> src/cat.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | fn read_to_string_v1(filename: &str) -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_to_string_v1`
[INFO] [stdout]   --> src/cat.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | fn read_to_string_v1(filename: &str) -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` 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 1.76s
[INFO] running `Command { std: "docker" "inspect" "5c8ceed64e0470ba093c91a4a4f568d4a1bf802ca3e959613823a8cbf17b2ac7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5c8ceed64e0470ba093c91a4a4f568d4a1bf802ca3e959613823a8cbf17b2ac7", kill_on_drop: false }`
[INFO] [stdout] 5c8ceed64e0470ba093c91a4a4f568d4a1bf802ca3e959613823a8cbf17b2ac7