[INFO] fetching crate head_tail 0.1.0...
[INFO] testing head_tail-0.1.0 against master#350d0ef0ec0493e6d21cfb265cb8211a0e74d766 for pr-145330-1
[INFO] extracting crate head_tail 0.1.0 into /workspace/builds/worker-4-tc1/source
[INFO] removed /workspace/builds/worker-4-tc1/source/rust-toolchain.toml
[INFO] started tweaking crates.io crate head_tail 0.1.0
[INFO] finished tweaking crates.io crate head_tail 0.1.0
[INFO] tweaked toml for crates.io crate head_tail 0.1.0 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate head_tail 0.1.0 on toolchain 350d0ef0ec0493e6d21cfb265cb8211a0e74d766
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+350d0ef0ec0493e6d21cfb265cb8211a0e74d766" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate head_tail 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+350d0ef0ec0493e6d21cfb265cb8211a0e74d766" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+350d0ef0ec0493e6d21cfb265cb8211a0e74d766" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0adf021b4a1f1a7ee3b1f9b7af9e204859f1e2f39a974da092e68fa2548b6a83
[INFO] running `Command { std: "docker" "start" "-a" "0adf021b4a1f1a7ee3b1f9b7af9e204859f1e2f39a974da092e68fa2548b6a83", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0adf021b4a1f1a7ee3b1f9b7af9e204859f1e2f39a974da092e68fa2548b6a83", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0adf021b4a1f1a7ee3b1f9b7af9e204859f1e2f39a974da092e68fa2548b6a83", kill_on_drop: false }`
[INFO] [stdout] 0adf021b4a1f1a7ee3b1f9b7af9e204859f1e2f39a974da092e68fa2548b6a83
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+350d0ef0ec0493e6d21cfb265cb8211a0e74d766" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1e0f01b29af10f03d432009138325d6a3cd6332e32d8a7affab3dd87dac21f10
[INFO] running `Command { std: "docker" "start" "-a" "1e0f01b29af10f03d432009138325d6a3cd6332e32d8a7affab3dd87dac21f10", kill_on_drop: false }`
[INFO] [stderr]    Compiling head_tail v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/head_tail.rs:18:10
[INFO] [stdout]    |
[INFO] [stdout] 18 |     for (i, line) in reader.lines().enumerate().take(n) {
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.44s
[INFO] running `Command { std: "docker" "inspect" "1e0f01b29af10f03d432009138325d6a3cd6332e32d8a7affab3dd87dac21f10", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e0f01b29af10f03d432009138325d6a3cd6332e32d8a7affab3dd87dac21f10", kill_on_drop: false }`
[INFO] [stdout] 1e0f01b29af10f03d432009138325d6a3cd6332e32d8a7affab3dd87dac21f10
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+350d0ef0ec0493e6d21cfb265cb8211a0e74d766" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d7a56edf01eac2faad4db69bcc9c3a51ce656619f6d29f9d8197dcd85d56c642
[INFO] running `Command { std: "docker" "start" "-a" "d7a56edf01eac2faad4db69bcc9c3a51ce656619f6d29f9d8197dcd85d56c642", kill_on_drop: false }`
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/head_tail.rs:18:10
[INFO] [stdout]    |
[INFO] [stdout] 18 |     for (i, line) in reader.lines().enumerate().take(n) {
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling head_tail v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/head_tail.rs:18:10
[INFO] [stdout]    |
[INFO] [stdout] 18 |     for (i, line) in reader.lines().enumerate().take(n) {
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.43s
[INFO] running `Command { std: "docker" "inspect" "d7a56edf01eac2faad4db69bcc9c3a51ce656619f6d29f9d8197dcd85d56c642", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d7a56edf01eac2faad4db69bcc9c3a51ce656619f6d29f9d8197dcd85d56c642", kill_on_drop: false }`
[INFO] [stdout] d7a56edf01eac2faad4db69bcc9c3a51ce656619f6d29f9d8197dcd85d56c642
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+350d0ef0ec0493e6d21cfb265cb8211a0e74d766" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] cd3b4c7480ebef18751c72d8519468ddb394ac07b926a3a5261bb62abff16ec7
[INFO] running `Command { std: "docker" "start" "-a" "cd3b4c7480ebef18751c72d8519468ddb394ac07b926a3a5261bb62abff16ec7", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/head_tail.rs:18:10
[INFO] [stderr]    |
[INFO] [stderr] 18 |     for (i, line) in reader.lines().enumerate().take(n) {
[INFO] [stderr]    |          ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `head_tail` (lib) generated 1 warning
[INFO] [stderr] warning: `head_tail` (lib test) generated 1 warning (1 duplicate)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running unittests src/head_tail.rs (/opt/rustwide/target/debug/deps/head_tail-98d9014d3dd2852f)
[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] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/head_tail-ae1cbc6036f4eb10)
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test tests::test_math ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests head_tail
[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" "cd3b4c7480ebef18751c72d8519468ddb394ac07b926a3a5261bb62abff16ec7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd3b4c7480ebef18751c72d8519468ddb394ac07b926a3a5261bb62abff16ec7", kill_on_drop: false }`
[INFO] [stdout] cd3b4c7480ebef18751c72d8519468ddb394ac07b926a3a5261bb62abff16ec7