[INFO] cloning repository https://github.com/yangrudan/rust_learn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/yangrudan/rust_learn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangrudan%2Frust_learn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangrudan%2Frust_learn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 83d5bb30f64911310232a2d89f890b55686128fd
[INFO] checking yangrudan/rust_learn against master#249595384b4589c71a00d622c4253f62c7f5ddbd for pr-127054
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangrudan%2Frust_learn" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/yangrudan/rust_learn on toolchain 249595384b4589c71a00d622c4253f62c7f5ddbd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+249595384b4589c71a00d622c4253f62c7f5ddbd" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/yangrudan/rust_learn
[INFO] finished tweaking git repo https://github.com/yangrudan/rust_learn
[INFO] tweaked toml for git repo https://github.com/yangrudan/rust_learn written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/yangrudan/rust_learn 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" "+249595384b4589c71a00d622c4253f62c7f5ddbd" "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 yangrudan/rust_learn against try#3a8bed575a08bd69d7fd880c6a28c07854726e3b for pr-127054
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangrudan%2Frust_learn" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/yangrudan/rust_learn on toolchain 3a8bed575a08bd69d7fd880c6a28c07854726e3b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a8bed575a08bd69d7fd880c6a28c07854726e3b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/yangrudan/rust_learn
[INFO] finished tweaking git repo https://github.com/yangrudan/rust_learn
[INFO] tweaked toml for git repo https://github.com/yangrudan/rust_learn written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/yangrudan/rust_learn 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" "+3a8bed575a08bd69d7fd880c6a28c07854726e3b" "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:dff56e7819e73ed36160586b3445e93eb0be776c16704aeeded9c3fb668b2384" "/opt/rustwide/cargo-home/bin/cargo" "+3a8bed575a08bd69d7fd880c6a28c07854726e3b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 84eec322f2652dba84e901e01459f51815b9eb3c2769e6d59e050d122deacca2
[INFO] running `Command { std: "docker" "start" "-a" "84eec322f2652dba84e901e01459f51815b9eb3c2769e6d59e050d122deacca2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "84eec322f2652dba84e901e01459f51815b9eb3c2769e6d59e050d122deacca2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84eec322f2652dba84e901e01459f51815b9eb3c2769e6d59e050d122deacca2", kill_on_drop: false }`
[INFO] [stdout] 84eec322f2652dba84e901e01459f51815b9eb3c2769e6d59e050d122deacca2
[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" "-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:dff56e7819e73ed36160586b3445e93eb0be776c16704aeeded9c3fb668b2384" "/opt/rustwide/cargo-home/bin/cargo" "+3a8bed575a08bd69d7fd880c6a28c07854726e3b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a3cb8edbebd18e2f5a4cb414f33b65ee362b47e6bfb394449c693cbf634645c4
[INFO] running `Command { std: "docker" "start" "-a" "a3cb8edbebd18e2f5a4cb414f33b65ee362b47e6bfb394449c693cbf634645c4", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_learn v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking complex v0.1.0 (/opt/rustwide/workdir/complex/complex)
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> complex/complex/src/lib.rs:13:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl<T> Complex<T> {
[INFO] [stdout]    | ------------------ associated function in this implementation
[INFO] [stdout] 13 |     fn new(re: T, im: T) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stdout] warning: unused variable: `some_number`
[INFO] [stdout]   --> examples/11_枚举与模式匹配.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let some_number = Some(5);
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_number`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> examples/11_枚举与模式匹配.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let some_string = Some("A String");
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `absent_number`
[INFO] [stdout]   --> examples/11_枚举与模式匹配.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let absent_number: Option<i32> = None;
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_absent_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, `2`, and `3` are never read
[INFO] [stdout]   --> examples/11_枚举与模式匹配.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |     V4(u8, u8, u8, u8),
[INFO] [stdout]    |     -- ^^  ^^  ^^  ^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddKind` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` 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] 27 |     V4((), (), (), ()),
[INFO] [stdout]    |        ~~  ~~  ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> examples/11_枚举与模式匹配.rs:28:8
[INFO] [stdout]    |
[INFO] [stdout] 28 |     V6(String),
[INFO] [stdout]    |     -- ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddKind` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 28 |     V6(()),
[INFO] [stdout]    |        ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `kind` and `address` are never read
[INFO] [stdout]   --> examples/11_枚举与模式匹配.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 31 | struct IpAddr {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 32 |     kind: IpAddKind,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 33 |     address: String,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: invalid character `'?'` in crate name: `21_?`
[INFO] [stdout]   |
[INFO] [stdout]   = help: you can either pass `--crate-name` on the command line or add `#![crate_name="…"]` to set the crate name
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `value` is never read
[INFO] [stdout]   --> examples/26_from.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     struct Number {
[INFO] [stdout]    |            ------ field in this struct
[INFO] [stdout] 23 |         value: i32,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Number` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_learn` (example "21_?") due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "a3cb8edbebd18e2f5a4cb414f33b65ee362b47e6bfb394449c693cbf634645c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a3cb8edbebd18e2f5a4cb414f33b65ee362b47e6bfb394449c693cbf634645c4", kill_on_drop: false }`
[INFO] [stdout] a3cb8edbebd18e2f5a4cb414f33b65ee362b47e6bfb394449c693cbf634645c4