[INFO] cloning repository https://github.com/undo-lang/vm
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/undo-lang/vm" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fundo-lang%2Fvm", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fundo-lang%2Fvm'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] afada7a9e34bbb2ed0512bb2a3646a00f606affb
[INFO] checking undo-lang/vm against try#07fecb9cf34c4979a772ba38c99d6d9144768413 for pr-87710
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fundo-lang%2Fvm" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/undo-lang/vm on toolchain 07fecb9cf34c4979a772ba38c99d6d9144768413
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/undo-lang/vm
[INFO] finished tweaking git repo https://github.com/undo-lang/vm
[INFO] tweaked toml for git repo https://github.com/undo-lang/vm written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/undo-lang/vm already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f8f975d95f73f0752c95c4a40edb6a19027d0024f1545aa97734c89b5b90fb0f
[INFO] running `Command { std: "docker" "start" "-a" "f8f975d95f73f0752c95c4a40edb6a19027d0024f1545aa97734c89b5b90fb0f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f8f975d95f73f0752c95c4a40edb6a19027d0024f1545aa97734c89b5b90fb0f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f8f975d95f73f0752c95c4a40edb6a19027d0024f1545aa97734c89b5b90fb0f", kill_on_drop: false }`
[INFO] [stdout] f8f975d95f73f0752c95c4a40edb6a19027d0024f1545aa97734c89b5b90fb0f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4907273e99c78b5cfd1280e715355186fd1ed89804d6bf06b6617b5fa4d334d9
[INFO] running `Command { std: "docker" "start" "-a" "4907273e99c78b5cfd1280e715355186fd1ed89804d6bf06b6617b5fa4d334d9", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.3
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]     Checking dtoa v0.4.2
[INFO] [stderr]     Checking num-traits v0.1.40
[INFO] [stderr]     Checking itoa v0.3.4
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.100
[INFO] [stderr]     Checking serde v1.0.15
[INFO] [stderr]     Checking serde_json v1.0.3
[INFO] [stderr]     Checking undo-vm v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `local`
[INFO] [stdout]    --> src/vm.rs:109:9
[INFO] [stdout]     |
[INFO] [stdout] 109 |     for local in frame.locals {
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_local`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arena`
[INFO] [stdout]   --> src/vm.rs:95:24
[INFO] [stdout]    |
[INFO] [stdout] 95 | fn compact(mut gc: GC, arena: Vec<Value>, frames: VecDeque<Frame>, mut stack: Vec<Ptr>) -> Vec<Value> {
[INFO] [stdout]    |                        ^^^^^ help: if this is intentional, prefix it with an underscore: `_arena`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `local`
[INFO] [stdout]    --> src/vm.rs:109:9
[INFO] [stdout]     |
[INFO] [stdout] 109 |     for local in frame.locals {
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_local`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arena`
[INFO] [stdout]   --> src/vm.rs:95:24
[INFO] [stdout]    |
[INFO] [stdout] 95 | fn compact(mut gc: GC, arena: Vec<Value>, frames: VecDeque<Frame>, mut stack: Vec<Ptr>) -> Vec<Value> {
[INFO] [stdout]    |                        ^^^^^ help: if this is intentional, prefix it with an underscore: `_arena`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ThwartPtr`
[INFO] [stdout]   --> src/vm.rs:65:3
[INFO] [stdout]    |
[INFO] [stdout] 65 |   ThwartPtr(usize),
[INFO] [stdout]    |   ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `compact`
[INFO] [stdout]   --> src/vm.rs:95:4
[INFO] [stdout]    |
[INFO] [stdout] 95 | fn compact(mut gc: GC, arena: Vec<Value>, frames: VecDeque<Frame>, mut stack: Vec<Ptr>) -> Vec<Value> {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `set`
[INFO] [stdout]    --> src/vm.rs:129:6
[INFO] [stdout]     |
[INFO] [stdout] 129 |   fn set(&mut self, i: usize, v: Value) {
[INFO] [stdout]     |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ThwartPtr`
[INFO] [stdout]   --> src/vm.rs:65:3
[INFO] [stdout]    |
[INFO] [stdout] 65 |   ThwartPtr(usize),
[INFO] [stdout]    |   ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `compact`
[INFO] [stdout]   --> src/vm.rs:95:4
[INFO] [stdout]    |
[INFO] [stdout] 95 | fn compact(mut gc: GC, arena: Vec<Value>, frames: VecDeque<Frame>, mut stack: Vec<Ptr>) -> Vec<Value> {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `set`
[INFO] [stdout]    --> src/vm.rs:129:6
[INFO] [stdout]     |
[INFO] [stdout] 129 |   fn set(&mut self, i: usize, v: Value) {
[INFO] [stdout]     |      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 22.44s
[INFO] running `Command { std: "docker" "inspect" "4907273e99c78b5cfd1280e715355186fd1ed89804d6bf06b6617b5fa4d334d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4907273e99c78b5cfd1280e715355186fd1ed89804d6bf06b6617b5fa4d334d9", kill_on_drop: false }`
[INFO] [stdout] 4907273e99c78b5cfd1280e715355186fd1ed89804d6bf06b6617b5fa4d334d9