[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#d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2 for pr-86479
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffahrenkrug%2Frust_learn_book_collections" "/workspace/builds/worker-15/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-15/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fahrenkrug/rust_learn_book_collections on toolchain d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2" "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-15/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" "+d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2f6f316118e755905969ce2cf1a1127c8cc76223906a419e325bbe53185932c6
[INFO] running `Command { std: "docker" "start" "-a" "2f6f316118e755905969ce2cf1a1127c8cc76223906a419e325bbe53185932c6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f6f316118e755905969ce2cf1a1127c8cc76223906a419e325bbe53185932c6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f6f316118e755905969ce2cf1a1127c8cc76223906a419e325bbe53185932c6", kill_on_drop: false }`
[INFO] [stdout] 2f6f316118e755905969ce2cf1a1127c8cc76223906a419e325bbe53185932c6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f6897fd9e3d48aec42b7b09b51015ef945c243bc532a30f29ff401cbd55103ff
[INFO] running `Command { std: "docker" "start" "-a" "f6897fd9e3d48aec42b7b09b51015ef945c243bc532a30f29ff401cbd55103ff", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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 2.43s
[INFO] running `Command { std: "docker" "inspect" "f6897fd9e3d48aec42b7b09b51015ef945c243bc532a30f29ff401cbd55103ff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f6897fd9e3d48aec42b7b09b51015ef945c243bc532a30f29ff401cbd55103ff", kill_on_drop: false }`
[INFO] [stdout] f6897fd9e3d48aec42b7b09b51015ef945c243bc532a30f29ff401cbd55103ff
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c031203de5602ade282987a350687c540144992352d5a3e28b8051fd8cc1c428
[INFO] running `Command { std: "docker" "start" "-a" "c031203de5602ade282987a350687c540144992352d5a3e28b8051fd8cc1c428", 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 0.60s
[INFO] running `Command { std: "docker" "inspect" "c031203de5602ade282987a350687c540144992352d5a3e28b8051fd8cc1c428", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c031203de5602ade282987a350687c540144992352d5a3e28b8051fd8cc1c428", kill_on_drop: false }`
[INFO] [stdout] c031203de5602ade282987a350687c540144992352d5a3e28b8051fd8cc1c428
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+d2e9fff28e244f1ea4927194f1f9b77f93e2ffe2" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 6dc14c9f3ef0a71ea966ec2a10ca740463a9a76afb53bee91786a52c6d41b10f
[INFO] running `Command { std: "docker" "start" "-a" "6dc14c9f3ef0a71ea966ec2a10ca740463a9a76afb53bee91786a52c6d41b10f", 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 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/collections-8271aa08e8666191)
[INFO] [stdout] 
[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" "6dc14c9f3ef0a71ea966ec2a10ca740463a9a76afb53bee91786a52c6d41b10f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6dc14c9f3ef0a71ea966ec2a10ca740463a9a76afb53bee91786a52c6d41b10f", kill_on_drop: false }`
[INFO] [stdout] 6dc14c9f3ef0a71ea966ec2a10ca740463a9a76afb53bee91786a52c6d41b10f