[INFO] cloning repository https://github.com/jongrubb/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jongrubb/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjongrubb%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjongrubb%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 220d418b638524ddf70aebb9cb64915929b151a1
[INFO] testing jongrubb/rustlings against beta-2025-09-21 for beta-1.91-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjongrubb%2Frustlings" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/jongrubb/rustlings
[INFO] finished tweaking git repo https://github.com/jongrubb/rustlings
[INFO] tweaked toml for git repo https://github.com/jongrubb/rustlings written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/jongrubb/rustlings on toolchain beta-2025-09-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/jongrubb/rustlings 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" "+beta-2025-09-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4692699d2844e03b7daaaf3228e5d0c00daa150fb7a2334165506a871704b38f
[INFO] running `Command { std: "docker" "start" "-a" "4692699d2844e03b7daaaf3228e5d0c00daa150fb7a2334165506a871704b38f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4692699d2844e03b7daaaf3228e5d0c00daa150fb7a2334165506a871704b38f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4692699d2844e03b7daaaf3228e5d0c00daa150fb7a2334165506a871704b38f", kill_on_drop: false }`
[INFO] [stdout] 4692699d2844e03b7daaaf3228e5d0c00daa150fb7a2334165506a871704b38f
[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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 418d49f45170361de6586c4921506c2a2a37047ad8dae7e29c67b2c4a47dbe61
[INFO] running `Command { std: "docker" "start" "-a" "418d49f45170361de6586c4921506c2a2a37047ad8dae7e29c67b2c4a47dbe61", kill_on_drop: false }`
[INFO] [stderr]    Compiling exercises v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> exercises/23_conversions/from_into.rs:37:25
[INFO] [stdout]    |
[INFO] [stdout] 37 |     fn from(s: &str) -> Self {}
[INFO] [stdout]    |        ----             ^^^^ expected `Person`, found `()`
[INFO] [stdout]    |        |
[INFO] [stdout]    |        implicitly returns `()` as its body has no tail or `return` expression
[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 "from_into") due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[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] [stderr] error: could not compile `exercises` (bin "errors3") due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "418d49f45170361de6586c4921506c2a2a37047ad8dae7e29c67b2c4a47dbe61", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "418d49f45170361de6586c4921506c2a2a37047ad8dae7e29c67b2c4a47dbe61", kill_on_drop: false }`
[INFO] [stdout] 418d49f45170361de6586c4921506c2a2a37047ad8dae7e29c67b2c4a47dbe61