[INFO] cloning repository https://github.com/ryancharris/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ryancharris/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryancharris%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryancharris%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 71e6d5a8c039a503c6c3bb490e447bfb22443f8c
[INFO] checking ryancharris/rustlings against try#a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d for pr-145342-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryancharris%2Frustlings" "/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/ryancharris/rustlings
[INFO] finished tweaking git repo https://github.com/ryancharris/rustlings
[INFO] tweaked toml for git repo https://github.com/ryancharris/rustlings written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/ryancharris/rustlings on toolchain a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e864fc274b5ba0d7b1316b9fa5ca55b777f86dae8e428d94390bf0d488d6a7e1
[INFO] running `Command { std: "docker" "start" "-a" "e864fc274b5ba0d7b1316b9fa5ca55b777f86dae8e428d94390bf0d488d6a7e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e864fc274b5ba0d7b1316b9fa5ca55b777f86dae8e428d94390bf0d488d6a7e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e864fc274b5ba0d7b1316b9fa5ca55b777f86dae8e428d94390bf0d488d6a7e1", kill_on_drop: false }`
[INFO] [stdout] e864fc274b5ba0d7b1316b9fa5ca55b777f86dae8e428d94390bf0d488d6a7e1
[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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+a4980311fb7bb9e7893708e6bd3fbbfb2819fd3d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 04f6bd5b42a877c64f7ef5d7a6c6175e1d915fe7e769a6907baabc42789cf798
[INFO] running `Command { std: "docker" "start" "-a" "04f6bd5b42a877c64f7ef5d7a6c6175e1d915fe7e769a6907baabc42789cf798", kill_on_drop: false }`
[INFO] [stderr]     Checking exercises v0.0.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: could not compile `exercises` (bin "intro2_sol") due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `exercises` (bin "variables2_sol" test) due to 1 previous error
[INFO] [stdout] error: couldn't read `solutions/01_variables/variables2.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read `solutions/00_intro/intro2.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read `solutions/03_if/if1.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read `solutions/05_vecs/vecs2.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read `solutions/06_move_semantics/move_semantics3.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read `solutions/23_conversions/from_into.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "if1_sol") due to 1 previous error
[INFO] [stderr] error: could not compile `exercises` (bin "vecs2_sol" test) due to 1 previous error
[INFO] [stderr] error: could not compile `exercises` (bin "move_semantics3_sol" test) due to 1 previous error
[INFO] [stdout] error: couldn't read `solutions/22_clippy/clippy2.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read `solutions/09_strings/strings1.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "strings1_sol" test) due to 1 previous error
[INFO] [stderr] error: could not compile `exercises` (bin "clippy2_sol" test) due to 1 previous error
[INFO] [stdout] error[E0282]: type annotations needed for `Vec<_>`
[INFO] [stdout]   --> exercises/20_threads/threads1.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let mut results = Vec::new();
[INFO] [stdout]    |         ^^^^^^^^^^^   ---------- type must be known at this point
[INFO] [stdout]    |
[INFO] [stdout] help: consider giving `results` an explicit type, where the type for type parameter `T` is specified
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let mut results: Vec<T> = Vec::new();
[INFO] [stdout]    |                    ++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read `solutions/01_variables/variables2.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "variables2_sol") due to 1 previous error
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]   --> exercises/13_error_handling/errors3.rs:23:46
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn main() {
[INFO] [stdout]    | --------- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout] ...
[INFO] [stdout] 23 |     let cost = total_cost(pretend_user_input)?;
[INFO] [stdout]    |                                              ^ cannot use the `?` operator in a function that returns `()`
[INFO] [stdout]    |
[INFO] [stdout] help: consider adding return type
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn main() -> Result<(), Box<dyn std::error::Error>> {
[INFO] [stdout]    |           +++++++++++++++++++++++++++++++++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "errors3" test) due to 1 previous error
[INFO] [stderr] error: could not compile `exercises` (bin "from_into_sol") due to 1 previous error
[INFO] [stdout] error: couldn't read `solutions/21_macros/macros1.rs`: No such file or directory (os error 2)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "macros1_sol") due to 1 previous error
[INFO] [stderr] error: could not compile `exercises` (bin "threads1") due to 1 previous error
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> exercises/18_iterators/iterators2.rs:17:47
[INFO] [stdout]    |
[INFO] [stdout] 17 | fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
[INFO] [stdout]    |    -----------------------                    ^^^^^^^^^^^ expected `Vec<String>`, found `()`
[INFO] [stdout]    |    |
[INFO] [stdout]    |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout]    |
[INFO] [stdout]    = note: expected struct `Vec<String>`
[INFO] [stdout]            found unit type `()`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> exercises/18_iterators/iterators2.rs:24:47
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn capitalize_words_string(words: &[&str]) -> String {
[INFO] [stdout]    |    -----------------------                    ^^^^^^ expected `String`, found `()`
[INFO] [stdout]    |    |
[INFO] [stdout]    |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stdout]  --> exercises/22_clippy/clippy2.rs:5:14
[INFO] [stdout]   |
[INFO] [stdout] 5 |     for x in option {
[INFO] [stdout]   |              ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stdout] help: to check pattern in a loop use `while let`
[INFO] [stdout]   |
[INFO] [stdout] 5 -     for x in option {
[INFO] [stdout] 5 +     while let Some(x) = option {
[INFO] [stdout]   |
[INFO] [stdout] help: consider using `if let` to clear intent
[INFO] [stdout]   |
[INFO] [stdout] 5 -     for x in option {
[INFO] [stdout] 5 +     if let Some(x) = option {
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]   --> exercises/18_iterators/iterators2.rs:10:14
[INFO] [stdout]    |
[INFO] [stdout] 10 |         Some(first) => todo!(),
[INFO] [stdout]    |              ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "iterators2" test) due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "04f6bd5b42a877c64f7ef5d7a6c6175e1d915fe7e769a6907baabc42789cf798", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04f6bd5b42a877c64f7ef5d7a6c6175e1d915fe7e769a6907baabc42789cf798", kill_on_drop: false }`
[INFO] [stdout] 04f6bd5b42a877c64f7ef5d7a6c6175e1d915fe7e769a6907baabc42789cf798