[INFO] fetching crate koi-gc 0.1.0...
[INFO] testing koi-gc-0.1.0 against 1.95.0 for beta-1.96-1
[INFO] extracting crate koi-gc 0.1.0 into /workspace/builds/worker-0-tc1/source
[INFO] started tweaking crates.io crate koi-gc 0.1.0
[INFO] finished tweaking crates.io crate koi-gc 0.1.0
[INFO] tweaked toml for crates.io crate koi-gc 0.1.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate koi-gc 0.1.0 on toolchain 1.95.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.95.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate koi-gc 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" "+1.95.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3b018de98f11dc7cac4eb7b5cd65aba8da73ca5729ff25ffbb608b66296829fc
[INFO] running `Command { std: "docker" "start" "-a" "3b018de98f11dc7cac4eb7b5cd65aba8da73ca5729ff25ffbb608b66296829fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3b018de98f11dc7cac4eb7b5cd65aba8da73ca5729ff25ffbb608b66296829fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3b018de98f11dc7cac4eb7b5cd65aba8da73ca5729ff25ffbb608b66296829fc", kill_on_drop: false }`
[INFO] [stdout] 3b018de98f11dc7cac4eb7b5cd65aba8da73ca5729ff25ffbb608b66296829fc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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=warn" "-e" "RUSTDOCFLAGS=--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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8a78e22ef3369adda4996c58d7d77b36230f3eaaddbb90a4507f151650ba844b
[INFO] running `Command { std: "docker" "start" "-a" "8a78e22ef3369adda4996c58d7d77b36230f3eaaddbb90a4507f151650ba844b", kill_on_drop: false }`
[INFO] [stderr]    Compiling koi-gc v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.43s
[INFO] running `Command { std: "docker" "inspect" "8a78e22ef3369adda4996c58d7d77b36230f3eaaddbb90a4507f151650ba844b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8a78e22ef3369adda4996c58d7d77b36230f3eaaddbb90a4507f151650ba844b", kill_on_drop: false }`
[INFO] [stdout] 8a78e22ef3369adda4996c58d7d77b36230f3eaaddbb90a4507f151650ba844b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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=warn" "-e" "RUSTDOCFLAGS=--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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] be6ade51c053b09d5239c3e7ced2176e7c28a54051821156c9aae9f7a63034c9
[INFO] running `Command { std: "docker" "start" "-a" "be6ade51c053b09d5239c3e7ced2176e7c28a54051821156c9aae9f7a63034c9", kill_on_drop: false }`
[INFO] [stderr]    Compiling koi-gc v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `visitor`
[INFO] [stdout]    --> src/lib.rs:486:29
[INFO] [stdout]     |
[INFO] [stdout] 486 |             fn visit(&self, visitor: &mut dyn FnMut(&dyn GcInterface)) {}
[INFO] [stdout]     |                             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_visitor`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `data` is never read
[INFO] [stdout]    --> src/lib.rs:440:9
[INFO] [stdout]     |
[INFO] [stdout] 438 |     struct Leak<T> {
[INFO] [stdout]     |            ---- field in this struct
[INFO] [stdout] 439 |         cycle: RefCell<Option<Rc<Rc<Leak<T>>>>>,
[INFO] [stdout] 440 |         data: T,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.90s
[INFO] running `Command { std: "docker" "inspect" "be6ade51c053b09d5239c3e7ced2176e7c28a54051821156c9aae9f7a63034c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "be6ade51c053b09d5239c3e7ced2176e7c28a54051821156c9aae9f7a63034c9", kill_on_drop: false }`
[INFO] [stdout] be6ade51c053b09d5239c3e7ced2176e7c28a54051821156c9aae9f7a63034c9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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=warn" "-e" "RUSTDOCFLAGS=--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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 379ab7ea62c685dbd9544ff0468fe094152b5437f7ddcec686e9377527e37c6e
[INFO] running `Command { std: "docker" "start" "-a" "379ab7ea62c685dbd9544ff0468fe094152b5437f7ddcec686e9377527e37c6e", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `visitor`
[INFO] [stderr]    --> src/lib.rs:486:29
[INFO] [stderr]     |
[INFO] [stderr] 486 |             fn visit(&self, visitor: &mut dyn FnMut(&dyn GcInterface)) {}
[INFO] [stderr]     |                             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_visitor`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field `data` is never read
[INFO] [stderr]    --> src/lib.rs:440:9
[INFO] [stderr]     |
[INFO] [stderr] 438 |     struct Leak<T> {
[INFO] [stderr]     |            ---- field in this struct
[INFO] [stderr] 439 |         cycle: RefCell<Option<Rc<Rc<Leak<T>>>>>,
[INFO] [stderr] 440 |         data: T,
[INFO] [stderr]     |         ^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `koi-gc` (lib test) generated 2 warnings (run `cargo fix --lib -p koi-gc --tests` to apply 1 suggestion)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.05s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/koi_gc-b88a805795f6f4b2)
[INFO] [stdout] 
[INFO] [stdout] running 2 tests
[INFO] [stdout] test tests::test_cycle_collection ... ok
[INFO] [stderr] error: test failed, to rerun pass `--lib`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/deps/koi_gc-b88a805795f6f4b2` (signal: 11, SIGSEGV: invalid memory reference)
[INFO] running `Command { std: "docker" "inspect" "379ab7ea62c685dbd9544ff0468fe094152b5437f7ddcec686e9377527e37c6e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "379ab7ea62c685dbd9544ff0468fe094152b5437f7ddcec686e9377527e37c6e", kill_on_drop: false }`
[INFO] [stdout] 379ab7ea62c685dbd9544ff0468fe094152b5437f7ddcec686e9377527e37c6e