[INFO] cloning repository https://github.com/kuroega/rust_from_the_book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kuroega/rust_from_the_book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkuroega%2Frust_from_the_book", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkuroega%2Frust_from_the_book'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a7f81d228dbf4042d3a2e02a087c307a20373d0d
[INFO] checking kuroega/rust_from_the_book against try#55b3f428b4fac6790b1e8492e0b91ff2d80aec7c for pr-77035
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkuroega%2Frust_from_the_book" "/workspace/builds/worker-13/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-13/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kuroega/rust_from_the_book on toolchain 55b3f428b4fac6790b1e8492e0b91ff2d80aec7c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/kuroega/rust_from_the_book
[INFO] finished tweaking git repo https://github.com/kuroega/rust_from_the_book
[INFO] tweaked toml for git repo https://github.com/kuroega/rust_from_the_book written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] crate git repo https://github.com/kuroega/rust_from_the_book already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "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] 6bad668992fbe777a27d80ac79edf3a4e91ec56accb92b5620ff061170c40fed
[INFO] running `Command { std: "docker" "start" "-a" "6bad668992fbe777a27d80ac79edf3a4e91ec56accb92b5620ff061170c40fed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6bad668992fbe777a27d80ac79edf3a4e91ec56accb92b5620ff061170c40fed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6bad668992fbe777a27d80ac79edf3a4e91ec56accb92b5620ff061170c40fed", kill_on_drop: false }`
[INFO] [stdout] 6bad668992fbe777a27d80ac79edf3a4e91ec56accb92b5620ff061170c40fed
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 31e63aa189b865cfa96ee6b3cb735173b440bafacb71a9938d7212637d34a092
[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" "31e63aa189b865cfa96ee6b3cb735173b440bafacb71a9938d7212637d34a092", kill_on_drop: false }`
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking learn-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> examples/ownership_demo.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let s1 = gives_ownership();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> examples/ownership_demo.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let s3  = takes_and_gives_back(s2);
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `username`
[INFO] [stdout]  --> examples/struct_demo3.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 |     username: String,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]  --> examples/struct_demo3.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 |     active: bool,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.38s
[INFO] running `Command { std: "docker" "inspect" "31e63aa189b865cfa96ee6b3cb735173b440bafacb71a9938d7212637d34a092", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31e63aa189b865cfa96ee6b3cb735173b440bafacb71a9938d7212637d34a092", kill_on_drop: false }`
[INFO] [stdout] 31e63aa189b865cfa96ee6b3cb735173b440bafacb71a9938d7212637d34a092