[INFO] cloning repository https://github.com/jeraldgan/rust-primer
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jeraldgan/rust-primer" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjeraldgan%2Frust-primer", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjeraldgan%2Frust-primer'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8722a96df067afa7439b1de35ff57b32ad9c3f66
[INFO] checking jeraldgan/rust-primer against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjeraldgan%2Frust-primer" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jeraldgan/rust-primer on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jeraldgan/rust-primer
[INFO] finished tweaking git repo https://github.com/jeraldgan/rust-primer
[INFO] tweaked toml for git repo https://github.com/jeraldgan/rust-primer written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/jeraldgan/rust-primer already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ef86d934244add3d606697c358963732fff4e712cc1d3088bc3c110fb8d2f3b7
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "ef86d934244add3d606697c358963732fff4e712cc1d3088bc3c110fb8d2f3b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ef86d934244add3d606697c358963732fff4e712cc1d3088bc3c110fb8d2f3b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ef86d934244add3d606697c358963732fff4e712cc1d3088bc3c110fb8d2f3b7", kill_on_drop: false }`
[INFO] [stdout] ef86d934244add3d606697c358963732fff4e712cc1d3088bc3c110fb8d2f3b7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3b7e2d62b3bcf7aa1156451484da04ad0b11dc8e7b61a9a054e447d91e169250
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "3b7e2d62b3bcf7aa1156451484da04ad0b11dc8e7b61a9a054e447d91e169250", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.65
[INFO] [stderr]    Compiling libc v0.2.91
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking os_str_bytes v2.4.0
[INFO] [stderr]     Checking strsim v0.10.0
[INFO] [stderr]     Checking solution2 v0.1.0 (/opt/rustwide/workdir/02-basics/solution)
[INFO] [stderr]     Checking demo-strings v0.1.0 (/opt/rustwide/workdir/06-strings/demo)
[INFO] [stderr]     Checking solution-structs v0.1.0 (/opt/rustwide/workdir/03-structs-lifetimes/solution)
[INFO] [stderr]     Checking exercise-libraries v0.1.0 (/opt/rustwide/workdir/07-external-libraries/exercise)
[INFO] [stderr]     Checking demo v0.1.0 (/opt/rustwide/workdir/02-basics/demo)
[INFO] [stderr]     Checking exercise-generics v0.1.0 (/opt/rustwide/workdir/04-generics-traits/exercise)
[INFO] [stderr]     Checking solution-generics v0.1.0 (/opt/rustwide/workdir/04-generics-traits/solution)
[INFO] [stderr]     Checking demo-generics v0.1.0 (/opt/rustwide/workdir/04-generics-traits/demo)
[INFO] [stderr]     Checking demo-structs v0.1.0 (/opt/rustwide/workdir/03-structs-lifetimes/demo)
[INFO] [stdout] error: expected identifier, found `?`
[INFO] [stdout]   --> 04-generics-traits/exercise/src/main.rs:24:37
[INFO] [stdout]    |
[INFO] [stdout] 24 |         let mut map: HashMap<&str, ???> = HashMap::new();
[INFO] [stdout]    |             --------                ^ expected identifier
[INFO] [stdout]    |             |      |
[INFO] [stdout]    |             |      help: use `=` if you meant to assign
[INFO] [stdout]    |             while parsing the type for `mut map`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, or an operator, found `,`
[INFO] [stdout]   --> 04-generics-traits/exercise/src/main.rs:24:34
[INFO] [stdout]    |
[INFO] [stdout] 24 |         let mut map: HashMap<&str, ???> = HashMap::new();
[INFO] [stdout]    |                                  ^ expected one of 7 possible tokens
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> 03-structs-lifetimes/solution/src/shapes/circle.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     use super::*;
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> 03-structs-lifetimes/solution/src/shapes/rectangle.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     use super::*;
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> 03-structs-lifetimes/solution/src/main.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     use super::*;
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: expected one of `!` or `::`, found `:`
[INFO] [stdout]   --> 07-external-libraries/exercise/src/main.rs:21:6
[INFO] [stdout]    |
[INFO] [stdout] 21 | https://docs.serde.rs/serde_json/#parsing-json-as-strongly-typed-data-structures
[INFO] [stdout]    |      ^ expected one of `!` or `::`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> 03-structs-lifetimes/demo/src/main.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn new(width: u32, height: u32) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `double_area_rect_reference`
[INFO] [stdout]   --> 03-structs-lifetimes/demo/src/main.rs:73:4
[INFO] [stdout]    |
[INFO] [stdout] 73 | fn double_area_rect_reference(rect: &Rectangle) -> u32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking structs-exercise v0.1.0 (/opt/rustwide/workdir/02-basics/exercise)
[INFO] [stderr] error: could not compile `exercise-libraries`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> 04-generics-traits/exercise/src/main.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     use std::collections::HashMap;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `x` is never read
[INFO] [stdout]  --> 02-basics/solution/src/main.rs:4:13
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let mut x = 1;
[INFO] [stdout]   |             ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> 06-strings/demo/src/main.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s2: String = String::from_str(s).unwrap(); // s could be invalid bytes for a String
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> 06-strings/demo/src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s2: String = s.to_owned();
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> 06-strings/demo/src/main.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let s3: &str = s2.as_str();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> 04-generics-traits/solution/src/main.rs:21:10
[INFO] [stdout]    |
[INFO] [stdout] 21 |         };
[INFO] [stdout]    |          ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> 04-generics-traits/solution/src/main.rs:39:10
[INFO] [stdout]    |
[INFO] [stdout] 39 |         };
[INFO] [stdout]    |          ^ help: remove this semicolon
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> 06-strings/demo/src/main.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s2: String = String::from_str(s).unwrap(); // s could be invalid bytes for a String
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]  --> 06-strings/demo/src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s2: String = s.to_owned();
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> 06-strings/demo/src/main.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let s3: &str = s2.as_str();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> 02-basics/exercise/src/main.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let x: u8 = 1;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `xs`
[INFO] [stdout]   --> 02-basics/exercise/src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let xs = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_xs`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `mutability`
[INFO] [stdout]  --> 02-basics/exercise/src/main.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn mutability() -> u8 {
[INFO] [stdout]   |    ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `casting`
[INFO] [stdout]   --> 02-basics/exercise/src/main.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | fn casting() -> f64 {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `collections`
[INFO] [stdout]   --> 02-basics/exercise/src/main.rs:27:4
[INFO] [stdout]    |
[INFO] [stdout] 27 | fn collections() -> u8 {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "3b7e2d62b3bcf7aa1156451484da04ad0b11dc8e7b61a9a054e447d91e169250", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3b7e2d62b3bcf7aa1156451484da04ad0b11dc8e7b61a9a054e447d91e169250", kill_on_drop: false }`
[INFO] [stdout] 3b7e2d62b3bcf7aa1156451484da04ad0b11dc8e7b61a9a054e447d91e169250