[INFO] cloning repository https://github.com/MozzieZhou/rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/MozzieZhou/rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMozzieZhou%2Frust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMozzieZhou%2Frust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 899a82920c6fa110489469af4ec172a8d8772bcf
[INFO] checking MozzieZhou/rust against master#4d1bd0db7f489b22c6d8aa2385937a95412c015b for pr-114682
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMozzieZhou%2Frust" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/MozzieZhou/rust on toolchain 4d1bd0db7f489b22c6d8aa2385937a95412c015b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4d1bd0db7f489b22c6d8aa2385937a95412c015b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/MozzieZhou/rust
[INFO] finished tweaking git repo https://github.com/MozzieZhou/rust
[INFO] tweaked toml for git repo https://github.com/MozzieZhou/rust written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/MozzieZhou/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" "+4d1bd0db7f489b22c6d8aa2385937a95412c015b" "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 MozzieZhou/rust against try#785364c7e5e0804473a3fddfb579798ea14e3493 for pr-114682
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMozzieZhou%2Frust" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/MozzieZhou/rust on toolchain 785364c7e5e0804473a3fddfb579798ea14e3493
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+785364c7e5e0804473a3fddfb579798ea14e3493" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/MozzieZhou/rust
[INFO] finished tweaking git repo https://github.com/MozzieZhou/rust
[INFO] tweaked toml for git repo https://github.com/MozzieZhou/rust written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/MozzieZhou/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" "+785364c7e5e0804473a3fddfb579798ea14e3493" "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 MozzieZhou/rust against try#785364c7e5e0804473a3fddfb579798ea14e3493 for pr-114682
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMozzieZhou%2Frust" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/MozzieZhou/rust on toolchain 785364c7e5e0804473a3fddfb579798ea14e3493
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+785364c7e5e0804473a3fddfb579798ea14e3493" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/MozzieZhou/rust
[INFO] finished tweaking git repo https://github.com/MozzieZhou/rust
[INFO] tweaked toml for git repo https://github.com/MozzieZhou/rust written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/MozzieZhou/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" "+785364c7e5e0804473a3fddfb579798ea14e3493" "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-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+785364c7e5e0804473a3fddfb579798ea14e3493" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e6192d7269c1c1aae81379f084c3c62ddd0fc12ba536a3e7ce75a6e405fe07e0
[INFO] running `Command { std: "docker" "start" "-a" "e6192d7269c1c1aae81379f084c3c62ddd0fc12ba536a3e7ce75a6e405fe07e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e6192d7269c1c1aae81379f084c3c62ddd0fc12ba536a3e7ce75a6e405fe07e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e6192d7269c1c1aae81379f084c3c62ddd0fc12ba536a3e7ce75a6e405fe07e0", kill_on_drop: false }`
[INFO] [stdout] e6192d7269c1c1aae81379f084c3c62ddd0fc12ba536a3e7ce75a6e405fe07e0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+785364c7e5e0804473a3fddfb579798ea14e3493" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8c1bb3319ca482c29676db34a9ccdec3f5a60d5367615c9e42671e4cdd710a28
[INFO] running `Command { std: "docker" "start" "-a" "8c1bb3319ca482c29676db34a9ccdec3f5a60d5367615c9e42671e4cdd710a28", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_learning v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 55 |         let mut school = School {
[INFO] [stdout]    |             ----^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 55 |         let mut school = School {
[INFO] [stdout]    |             ----^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `name` is never read
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Student {
[INFO] [stdout]   |        ------- field in this struct
[INFO] [stdout] 4 |     id: u32,
[INFO] [stdout] 5 |     name: String,
[INFO] [stdout]   |     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `Student` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `subject` is never read
[INFO] [stdout]   --> src/main.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | struct Course {
[INFO] [stdout]    |        ------ field in this struct
[INFO] [stdout] 25 |     id: u32,
[INFO] [stdout] 26 |     subject: Subject,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Math`, `English`, and `Science` are never constructed
[INFO] [stdout]   --> src/main.rs:41:5
[INFO] [stdout]    |
[INFO] [stdout] 40 | enum Subject {
[INFO] [stdout]    |      ------- variants in this enum
[INFO] [stdout] 41 |     Math,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 42 |     Chinese,
[INFO] [stdout] 43 |     English,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 44 |     Science,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `add_course` and `get_student_by_id` are never used
[INFO] [stdout]   --> src/main.rs:66:8
[INFO] [stdout]    |
[INFO] [stdout] 53 | impl School {
[INFO] [stdout]    | ----------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 66 |     fn add_course(&mut self, course: Course) {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 70 |     fn get_student_by_id(&self, id: u32) -> &Student {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `name` is never read
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Student {
[INFO] [stdout]   |        ------- field in this struct
[INFO] [stdout] 4 |     id: u32,
[INFO] [stdout] 5 |     name: String,
[INFO] [stdout]   |     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `Student` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `subject` is never read
[INFO] [stdout]   --> src/main.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | struct Course {
[INFO] [stdout]    |        ------ field in this struct
[INFO] [stdout] 25 |     id: u32,
[INFO] [stdout] 26 |     subject: Subject,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Math`, `English`, and `Science` are never constructed
[INFO] [stdout]   --> src/main.rs:41:5
[INFO] [stdout]    |
[INFO] [stdout] 40 | enum Subject {
[INFO] [stdout]    |      ------- variants in this enum
[INFO] [stdout] 41 |     Math,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 42 |     Chinese,
[INFO] [stdout] 43 |     English,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 44 |     Science,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `add_course` and `get_student_by_id` are never used
[INFO] [stdout]   --> src/main.rs:66:8
[INFO] [stdout]    |
[INFO] [stdout] 53 | impl School {
[INFO] [stdout]    | ----------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 66 |     fn add_course(&mut self, course: Course) {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 70 |     fn get_student_by_id(&self, id: u32) -> &Student {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.05s
[INFO] running `Command { std: "docker" "inspect" "8c1bb3319ca482c29676db34a9ccdec3f5a60d5367615c9e42671e4cdd710a28", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c1bb3319ca482c29676db34a9ccdec3f5a60d5367615c9e42671e4cdd710a28", kill_on_drop: false }`
[INFO] [stdout] 8c1bb3319ca482c29676db34a9ccdec3f5a60d5367615c9e42671e4cdd710a28
