[INFO] cloning repository https://github.com/dhilipsiva/learn-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dhilipsiva/learn-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdhilipsiva%2Flearn-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdhilipsiva%2Flearn-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 13385d424a96389fa3b325f02b204d878a8cfe42
[INFO] checking dhilipsiva/learn-rust against try#7b3da9103634dffd4f4365cfd8642427c781d99f+rustflags=-Dinherent-method-on-receiver for 152214-denied
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdhilipsiva%2Flearn-rust" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/dhilipsiva/learn-rust
[INFO] finished tweaking git repo https://github.com/dhilipsiva/learn-rust
[INFO] tweaked toml for git repo https://github.com/dhilipsiva/learn-rust written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/dhilipsiva/learn-rust on toolchain 7b3da9103634dffd4f4365cfd8642427c781d99f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+7b3da9103634dffd4f4365cfd8642427c781d99f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/dhilipsiva/learn-rust 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" "+7b3da9103634dffd4f4365cfd8642427c781d99f" "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
[ERROR] error running command: no output for 300 seconds
[INFO] checking dhilipsiva/learn-rust against try#7b3da9103634dffd4f4365cfd8642427c781d99f+rustflags=-Dinherent-method-on-receiver for 152214-denied
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdhilipsiva%2Flearn-rust" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/dhilipsiva/learn-rust
[INFO] finished tweaking git repo https://github.com/dhilipsiva/learn-rust
[INFO] tweaked toml for git repo https://github.com/dhilipsiva/learn-rust written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/dhilipsiva/learn-rust on toolchain 7b3da9103634dffd4f4365cfd8642427c781d99f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+7b3da9103634dffd4f4365cfd8642427c781d99f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/dhilipsiva/learn-rust 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" "+7b3da9103634dffd4f4365cfd8642427c781d99f" "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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+7b3da9103634dffd4f4365cfd8642427c781d99f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c2914cce9142324a399c854ff7a4e9059584cf1b58f1b97aa201152f16b1c3d4
[INFO] running `Command { std: "docker" "start" "-a" "c2914cce9142324a399c854ff7a4e9059584cf1b58f1b97aa201152f16b1c3d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c2914cce9142324a399c854ff7a4e9059584cf1b58f1b97aa201152f16b1c3d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c2914cce9142324a399c854ff7a4e9059584cf1b58f1b97aa201152f16b1c3d4", kill_on_drop: false }`
[INFO] [stdout] c2914cce9142324a399c854ff7a4e9059584cf1b58f1b97aa201152f16b1c3d4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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 -Dinherent-method-on-receiver" "-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@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+7b3da9103634dffd4f4365cfd8642427c781d99f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 90aeb746c964fd2b924acaebcc213c5e8219590429640d8e485c55937cb69cfd
[INFO] running `Command { std: "docker" "start" "-a" "90aeb746c964fd2b924acaebcc213c5e8219590429640d8e485c55937cb69cfd", kill_on_drop: false }`
[INFO] [stderr]     Checking ds-learn-rust v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/ch_15_01.rs:24:10
[INFO] [stdout]    |
[INFO] [stdout] 24 |     Cons(i32, Box<List>),
[INFO] [stdout]    |     ---- ^^^  ^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 24 -     Cons(i32, Box<List>),
[INFO] [stdout] 24 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/ch_15_01.rs:78:10
[INFO] [stdout]    |
[INFO] [stdout] 78 |     Cons(i32, Rc<RcList>),
[INFO] [stdout]    |     ---- ^^^  ^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `RcList` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 78 -     Cons(i32, Rc<RcList>),
[INFO] [stdout] 78 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/ch_15_01.rs:113:23
[INFO] [stdout]     |
[INFO] [stdout] 113 |     fn new(messenger: &T, max: usize) -> LimitTracker<T> {
[INFO] [stdout]     |                       ^^                 ^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                       |
[INFO] [stdout]     |                       the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 113 |     fn new(messenger: &T, max: usize) -> LimitTracker<'_, T> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/ch_15_01.rs:24:10
[INFO] [stdout]    |
[INFO] [stdout] 24 |     Cons(i32, Box<List>),
[INFO] [stdout]    |     ---- ^^^  ^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 24 -     Cons(i32, Box<List>),
[INFO] [stdout] 24 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/ch_15_01.rs:78:10
[INFO] [stdout]    |
[INFO] [stdout] 78 |     Cons(i32, Rc<RcList>),
[INFO] [stdout]    |     ---- ^^^  ^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `RcList` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 78 -     Cons(i32, Rc<RcList>),
[INFO] [stdout] 78 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/ch_15_01.rs:113:23
[INFO] [stdout]     |
[INFO] [stdout] 113 |     fn new(messenger: &T, max: usize) -> LimitTracker<T> {
[INFO] [stdout]     |                       ^^                 ^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                       |
[INFO] [stdout]     |                       the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 113 |     fn new(messenger: &T, max: usize) -> LimitTracker<'_, T> {
[INFO] [stdout]     |                                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.19s
[INFO] running `Command { std: "docker" "inspect" "90aeb746c964fd2b924acaebcc213c5e8219590429640d8e485c55937cb69cfd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "90aeb746c964fd2b924acaebcc213c5e8219590429640d8e485c55937cb69cfd", kill_on_drop: false }`
[INFO] [stdout] 90aeb746c964fd2b924acaebcc213c5e8219590429640d8e485c55937cb69cfd