[INFO] cloning repository https://github.com/marior765/GC
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/marior765/GC" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmarior765%2FGC", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmarior765%2FGC'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e4c812d7af62bee730cf462b7a77cd006b38d6a5
[INFO] checking marior765/GC against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmarior765%2FGC" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/marior765/GC on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/marior765/GC
[INFO] finished tweaking git repo https://github.com/marior765/GC
[INFO] tweaked toml for git repo https://github.com/marior765/GC written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/marior765/GC 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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] checking marior765/GC against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmarior765%2FGC" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/marior765/GC on toolchain 3a4bc97f6385a3aa300a4fd689b44350e54fd676
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/marior765/GC
[INFO] finished tweaking git repo https://github.com/marior765/GC
[INFO] tweaked toml for git repo https://github.com/marior765/GC written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/marior765/GC 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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "fetch" "--manifest-path" "Cargo.toml", 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 35bf2b0c14a951b17d1f9ab39b8918339632cc902d2a6c0436a906f0aea476f3
[INFO] running `Command { std: "docker" "start" "-a" "35bf2b0c14a951b17d1f9ab39b8918339632cc902d2a6c0436a906f0aea476f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "35bf2b0c14a951b17d1f9ab39b8918339632cc902d2a6c0436a906f0aea476f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "35bf2b0c14a951b17d1f9ab39b8918339632cc902d2a6c0436a906f0aea476f3", kill_on_drop: false }`
[INFO] [stdout] 35bf2b0c14a951b17d1f9ab39b8918339632cc902d2a6c0436a906f0aea476f3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b286c9255a6ddb78cd53279b62df42cbd8f455b3abd3b21b3d3a4165e8a3e0ec
[INFO] running `Command { std: "docker" "start" "-a" "b286c9255a6ddb78cd53279b62df42cbd8f455b3abd3b21b3d3a4165e8a3e0ec", kill_on_drop: false }`
[INFO] [stderr]     Checking gc v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `Option` is imported redundantly
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     std::option::Option,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/3a4bc97f6385a3aa300a4fd689b44350e54fd676/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `Option` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Option` is imported redundantly
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     std::option::Option,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/3a4bc97f6385a3aa300a4fd689b44350e54fd676/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `Option` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]    --> src/main.rs:251:13
[INFO] [stdout]     |
[INFO] [stdout] 251 |         for j in 0..20 {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_j`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k`
[INFO] [stdout]    --> src/main.rs:254:13
[INFO] [stdout]     |
[INFO] [stdout] 254 |         for k in 0..20 {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_k`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `STACK_MAX_SIZE` is never used
[INFO] [stdout]   --> src/main.rs:12:7
[INFO] [stdout]    |
[INFO] [stdout] 12 | const STACK_MAX_SIZE: usize = 256;
[INFO] [stdout]    |       ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `StackLink` is never used
[INFO] [stdout]   --> src/main.rs:17:6
[INFO] [stdout]    |
[INFO] [stdout] 17 | type StackLink = Rc<RefCell<Vec<SingleLink>>>;
[INFO] [stdout]    |      ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `type_obj`, `marked`, and `next` are never read
[INFO] [stdout]   --> src/main.rs:49:5
[INFO] [stdout]    |
[INFO] [stdout] 48 | struct Object {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 49 |     type_obj: ObjectType,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 50 |     marked: bool, // u8
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 51 |     next: SingleLink,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Object` has a derived impl for the trait `Clone`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `mark` is never used
[INFO] [stdout]    --> src/main.rs:105:12
[INFO] [stdout]     |
[INFO] [stdout] 79  | impl VM {
[INFO] [stdout]     | ------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 105 |     pub fn mark(&mut self, item: &mut Object) {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]    --> src/main.rs:251:13
[INFO] [stdout]     |
[INFO] [stdout] 251 |         for j in 0..20 {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_j`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k`
[INFO] [stdout]    --> src/main.rs:254:13
[INFO] [stdout]     |
[INFO] [stdout] 254 |         for k in 0..20 {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_k`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `STACK_MAX_SIZE` is never used
[INFO] [stdout]   --> src/main.rs:12:7
[INFO] [stdout]    |
[INFO] [stdout] 12 | const STACK_MAX_SIZE: usize = 256;
[INFO] [stdout]    |       ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `StackLink` is never used
[INFO] [stdout]   --> src/main.rs:17:6
[INFO] [stdout]    |
[INFO] [stdout] 17 | type StackLink = Rc<RefCell<Vec<SingleLink>>>;
[INFO] [stdout]    |      ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `type_obj`, `marked`, and `next` are never read
[INFO] [stdout]   --> src/main.rs:49:5
[INFO] [stdout]    |
[INFO] [stdout] 48 | struct Object {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 49 |     type_obj: ObjectType,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 50 |     marked: bool, // u8
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 51 |     next: SingleLink,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Object` has a derived impl for the trait `Clone`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `mark` is never used
[INFO] [stdout]    --> src/main.rs:105:12
[INFO] [stdout]     |
[INFO] [stdout] 79  | impl VM {
[INFO] [stdout]     | ------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 105 |     pub fn mark(&mut self, item: &mut Object) {
[INFO] [stdout]     |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] running `Command { std: "docker" "inspect" "b286c9255a6ddb78cd53279b62df42cbd8f455b3abd3b21b3d3a4165e8a3e0ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b286c9255a6ddb78cd53279b62df42cbd8f455b3abd3b21b3d3a4165e8a3e0ec", kill_on_drop: false }`
[INFO] [stdout] b286c9255a6ddb78cd53279b62df42cbd8f455b3abd3b21b3d3a4165e8a3e0ec