[INFO] cloning repository https://github.com/fahrenkrug/rust_learn_book_collections
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fahrenkrug/rust_learn_book_collections" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffahrenkrug%2Frust_learn_book_collections", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffahrenkrug%2Frust_learn_book_collections'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 39fa05d9fffbd36a289358263afb7e4aa84b0e19
[INFO] testing fahrenkrug/rust_learn_book_collections against try#722e1797249a965b6335aebd65d777f917e498f1 for pr-91031
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffahrenkrug%2Frust_learn_book_collections" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fahrenkrug/rust_learn_book_collections on toolchain 722e1797249a965b6335aebd65d777f917e498f1
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/fahrenkrug/rust_learn_book_collections
[INFO] finished tweaking git repo https://github.com/fahrenkrug/rust_learn_book_collections
[INFO] tweaked toml for git repo https://github.com/fahrenkrug/rust_learn_book_collections written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/fahrenkrug/rust_learn_book_collections already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 14f9d4af5f94b1cabbeea44ea3be313285128be3a40666582d6894848c5312cd
[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" "14f9d4af5f94b1cabbeea44ea3be313285128be3a40666582d6894848c5312cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "14f9d4af5f94b1cabbeea44ea3be313285128be3a40666582d6894848c5312cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "14f9d4af5f94b1cabbeea44ea3be313285128be3a40666582d6894848c5312cd", kill_on_drop: false }`
[INFO] [stdout] 14f9d4af5f94b1cabbeea44ea3be313285128be3a40666582d6894848c5312cd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ad2d385665540e3ccab55bd1f8c06e29a8fb03215a09d029d7049bcb88a522da
[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" "ad2d385665540e3ccab55bd1f8c06e29a8fb03215a09d029d7049bcb88a522da", kill_on_drop: false }`
[INFO] [stderr]    Compiling collections v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `does_not_exist`
[INFO] [stdout]   --> src/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let does_not_exist = v.get(100);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exist`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |     let mut s = String::new();
[INFO] [stdout]     |         ----^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:186:9
[INFO] [stdout]     |
[INFO] [stdout] 186 |     let mut scores: HashMap<_, _> = teams.into_iter().zip(initial_scores.into_iter()).collect();
[INFO] [stdout]     |         ----^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.00s
[INFO] running `Command { std: "docker" "inspect" "ad2d385665540e3ccab55bd1f8c06e29a8fb03215a09d029d7049bcb88a522da", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ad2d385665540e3ccab55bd1f8c06e29a8fb03215a09d029d7049bcb88a522da", kill_on_drop: false }`
[INFO] [stdout] ad2d385665540e3ccab55bd1f8c06e29a8fb03215a09d029d7049bcb88a522da
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d5d36aa24afb8213dfaf1e10573194db7c55ca2af36d3207c3c79dc0b3fb1a24
[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" "d5d36aa24afb8213dfaf1e10573194db7c55ca2af36d3207c3c79dc0b3fb1a24", kill_on_drop: false }`
[INFO] [stderr]    Compiling collections v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `does_not_exist`
[INFO] [stdout]   --> src/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let does_not_exist = v.get(100);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exist`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |     let mut s = String::new();
[INFO] [stdout]     |         ----^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:186:9
[INFO] [stdout]     |
[INFO] [stdout] 186 |     let mut scores: HashMap<_, _> = teams.into_iter().zip(initial_scores.into_iter()).collect();
[INFO] [stdout]     |         ----^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.07s
[INFO] running `Command { std: "docker" "inspect" "d5d36aa24afb8213dfaf1e10573194db7c55ca2af36d3207c3c79dc0b3fb1a24", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d5d36aa24afb8213dfaf1e10573194db7c55ca2af36d3207c3c79dc0b3fb1a24", kill_on_drop: false }`
[INFO] [stdout] d5d36aa24afb8213dfaf1e10573194db7c55ca2af36d3207c3c79dc0b3fb1a24
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] d33c07b0d367da67f82ce8ef3bbda6ecc4f2de163a9b408aa3ee31dff75fda78
[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" "d33c07b0d367da67f82ce8ef3bbda6ecc4f2de163a9b408aa3ee31dff75fda78", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `does_not_exist`
[INFO] [stderr]   --> src/main.rs:63:9
[INFO] [stderr]    |
[INFO] [stderr] 63 |     let does_not_exist = v.get(100);
[INFO] [stderr]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exist`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:101:9
[INFO] [stderr]     |
[INFO] [stderr] 101 |     let mut s = String::new();
[INFO] [stderr]     |         ----^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:186:9
[INFO] [stderr]     |
[INFO] [stderr] 186 |     let mut scores: HashMap<_, _> = teams.into_iter().zip(initial_scores.into_iter()).collect();
[INFO] [stderr]     |         ----^^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: `collections` (bin "collections" test) generated 3 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/collections-fa45a099985a6cd1)
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "d33c07b0d367da67f82ce8ef3bbda6ecc4f2de163a9b408aa3ee31dff75fda78", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d33c07b0d367da67f82ce8ef3bbda6ecc4f2de163a9b408aa3ee31dff75fda78", kill_on_drop: false }`
[INFO] [stdout] d33c07b0d367da67f82ce8ef3bbda6ecc4f2de163a9b408aa3ee31dff75fda78