[INFO] fetching crate solve_string 0.1.1...
[INFO] testing solve_string-0.1.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate solve_string 0.1.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate solve_string 0.1.1 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate solve_string 0.1.1
[INFO] finished tweaking crates.io crate solve_string 0.1.1
[INFO] tweaked toml for crates.io crate solve_string 0.1.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 604f487b2c38d897cf603f875d58933e051c413b2de599d7b2358d17dd612275
[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" "604f487b2c38d897cf603f875d58933e051c413b2de599d7b2358d17dd612275", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "604f487b2c38d897cf603f875d58933e051c413b2de599d7b2358d17dd612275", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "604f487b2c38d897cf603f875d58933e051c413b2de599d7b2358d17dd612275", kill_on_drop: false }`
[INFO] [stdout] 604f487b2c38d897cf603f875d58933e051c413b2de599d7b2358d17dd612275
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", 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] a6b3e46a09b3fae6ce70cff39327a43285f0019ca8726f13ffc01740d42d1278
[INFO] running `Command { std: "docker" "start" "-a" "a6b3e46a09b3fae6ce70cff39327a43285f0019ca8726f13ffc01740d42d1278", kill_on_drop: false }`
[INFO] [stderr]    Compiling solve_string v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `before_letter` is never read
[INFO] [stdout]   --> src/lib.rs:11:17
[INFO] [stdout]    |
[INFO] [stdout] 11 |         let mut before_letter= "l";
[INFO] [stdout]    |                 ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.72s
[INFO] running `Command { std: "docker" "inspect" "a6b3e46a09b3fae6ce70cff39327a43285f0019ca8726f13ffc01740d42d1278", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a6b3e46a09b3fae6ce70cff39327a43285f0019ca8726f13ffc01740d42d1278", kill_on_drop: false }`
[INFO] [stdout] a6b3e46a09b3fae6ce70cff39327a43285f0019ca8726f13ffc01740d42d1278
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 26635dd6522ee79b3c617a5d111554fbf09b389d3e781531b401c616d95d51a0
[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" "26635dd6522ee79b3c617a5d111554fbf09b389d3e781531b401c616d95d51a0", kill_on_drop: false }`
[INFO] [stdout] warning: value assigned to `before_letter` is never read
[INFO] [stdout]   --> src/lib.rs:11:17
[INFO] [stdout]    |
[INFO] [stdout] 11 |         let mut before_letter= "l";
[INFO] [stdout]    |                 ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling solve_string v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `before_letter` is never read
[INFO] [stdout]   --> src/lib.rs:11:17
[INFO] [stdout]    |
[INFO] [stdout] 11 |         let mut before_letter= "l";
[INFO] [stdout]    |                 ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.86s
[INFO] running `Command { std: "docker" "inspect" "26635dd6522ee79b3c617a5d111554fbf09b389d3e781531b401c616d95d51a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "26635dd6522ee79b3c617a5d111554fbf09b389d3e781531b401c616d95d51a0", kill_on_drop: false }`
[INFO] [stdout] 26635dd6522ee79b3c617a5d111554fbf09b389d3e781531b401c616d95d51a0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 07015d8b867047f0ce02d4a14b2bd5adc983ad19f6fd4fa204859f9875815f4d
[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" "07015d8b867047f0ce02d4a14b2bd5adc983ad19f6fd4fa204859f9875815f4d", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stdout] 
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stdout] running 0 tests
[INFO] [stderr] warning: value assigned to `before_letter` is never read
[INFO] [stdout] 
[INFO] [stderr]   --> src/lib.rs:11:17
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr]    |
[INFO] [stdout] 
[INFO] [stderr] 11 |         let mut before_letter= "l";
[INFO] [stderr]    |                 ^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: `solve_string` (lib) generated 1 warning
[INFO] [stderr] warning: `solve_string` (lib test) generated 1 warning (1 duplicate)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.41s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/solve_string-1d7ce6d416fc762e)
[INFO] [stderr]    Doc-tests solve_string
[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" "07015d8b867047f0ce02d4a14b2bd5adc983ad19f6fd4fa204859f9875815f4d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "07015d8b867047f0ce02d4a14b2bd5adc983ad19f6fd4fa204859f9875815f4d", kill_on_drop: false }`
[INFO] [stdout] 07015d8b867047f0ce02d4a14b2bd5adc983ad19f6fd4fa204859f9875815f4d