[INFO] updating cached repository https://github.com/imkiwa/RustPlayground
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1d53a9f08260f430c69456b0df2556c59abdb62d
[INFO] testing imkiwa/RustPlayground against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimkiwa%2FRustPlayground" "/workspace/builds/worker-10/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-10/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/imkiwa/RustPlayground on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[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-10/source/Cargo.toml
[INFO] crate git repo https://github.com/imkiwa/RustPlayground already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 0969fb2b705170225c2928ccb1610c5504054261d8bcdc72780be030e173975f
[INFO] running `"docker" "start" "-a" "0969fb2b705170225c2928ccb1610c5504054261d8bcdc72780be030e173975f"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rust_playground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]   --> src/playground/calculator.rs:65:32
[INFO] [stderr]    |
[INFO] [stderr] 65 |     fn build_ast(&mut self) -> Box<dyn AST> {
[INFO] [stderr]    |        ---------               ^^^^^^^^^^^^ expected struct `std::boxed::Box`, found `()`
[INFO] [stderr]    |        |
[INFO] [stderr]    |        implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stderr]    |
[INFO] [stderr]    = note: expected struct `std::boxed::Box<(dyn playground::calculator::AST + 'static)>`
[INFO] [stderr]            found unit type `()`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0308`.
[INFO] [stderr] error: could not compile `rust_playground`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0969fb2b705170225c2928ccb1610c5504054261d8bcdc72780be030e173975f"`
[INFO] running `"docker" "rm" "-f" "0969fb2b705170225c2928ccb1610c5504054261d8bcdc72780be030e173975f"`
[INFO] [stdout] 0969fb2b705170225c2928ccb1610c5504054261d8bcdc72780be030e173975f