[INFO] cloning repository https://github.com/imkiwa/RustPlayground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/imkiwa/RustPlayground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimkiwa%2FRustPlayground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimkiwa%2FRustPlayground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1d53a9f08260f430c69456b0df2556c59abdb62d
[INFO] testing imkiwa/RustPlayground against 1.60.0 for beta-1.61-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimkiwa%2FRustPlayground" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/imkiwa/RustPlayground on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/imkiwa/RustPlayground
[INFO] finished tweaking git repo https://github.com/imkiwa/RustPlayground
[INFO] tweaked toml for git repo https://github.com/imkiwa/RustPlayground written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/imkiwa/RustPlayground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 54e8947b0d58ce4db410ed934829c7fd14ba89f2ce4e81ed8d78688074673bb7
[INFO] running `Command { std: "docker" "start" "-a" "54e8947b0d58ce4db410ed934829c7fd14ba89f2ce4e81ed8d78688074673bb7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "54e8947b0d58ce4db410ed934829c7fd14ba89f2ce4e81ed8d78688074673bb7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54e8947b0d58ce4db410ed934829c7fd14ba89f2ce4e81ed8d78688074673bb7", kill_on_drop: false }`
[INFO] [stdout] 54e8947b0d58ce4db410ed934829c7fd14ba89f2ce4e81ed8d78688074673bb7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2eb16394c49090bbb2430c9ba63289d04b69b0f8bc5fd61c5d4a9a537dc09004
[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" "2eb16394c49090bbb2430c9ba63289d04b69b0f8bc5fd61c5d4a9a537dc09004", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_playground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> src/playground/calculator.rs:65:32
[INFO] [stdout]    |
[INFO] [stdout] 65 |     fn build_ast(&mut self) -> Box<dyn AST> {
[INFO] [stdout]    |        ---------               ^^^^^^^^^^^^ expected struct `Box`, found `()`
[INFO] [stdout]    |        |
[INFO] [stdout]    |        implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout]    |
[INFO] [stdout]    = note: expected struct `Box<(dyn AST + 'static)>`
[INFO] [stdout]            found unit type `()`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_playground` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "2eb16394c49090bbb2430c9ba63289d04b69b0f8bc5fd61c5d4a9a537dc09004", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2eb16394c49090bbb2430c9ba63289d04b69b0f8bc5fd61c5d4a9a537dc09004", kill_on_drop: false }`
[INFO] [stdout] 2eb16394c49090bbb2430c9ba63289d04b69b0f8bc5fd61c5d4a9a537dc09004