[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 try#8de4c7234dd9b97c9d76b58671343fdbbc9a433e+target=x86_64-unknown-linux-musl for musl_upgrade_1_2_5_with_libc_patch_0
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimkiwa%2FRustPlayground" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[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-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/imkiwa/RustPlayground on toolchain 8de4c7234dd9b97c9d76b58671343fdbbc9a433e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/imkiwa/RustPlayground 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" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 36a3c1bd311c86f3fa8ec6db223cf85bccbf22ef024785a1ffef81af831a0334
[INFO] running `Command { std: "docker" "start" "-a" "36a3c1bd311c86f3fa8ec6db223cf85bccbf22ef024785a1ffef81af831a0334", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "36a3c1bd311c86f3fa8ec6db223cf85bccbf22ef024785a1ffef81af831a0334", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "36a3c1bd311c86f3fa8ec6db223cf85bccbf22ef024785a1ffef81af831a0334", kill_on_drop: false }`
[INFO] [stdout] 36a3c1bd311c86f3fa8ec6db223cf85bccbf22ef024785a1ffef81af831a0334
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "build" "--frozen" "--message-format=json" "--target" "x86_64-unknown-linux-musl", kill_on_drop: false }`
[INFO] [stdout] e070744f082138ea5d84a63b8e89f89753c253387d6fa11594f9aa407e99b914
[INFO] running `Command { std: "docker" "start" "-a" "e070744f082138ea5d84a63b8e89f89753c253387d6fa11594f9aa407e99b914", 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 `Box<dyn AST>`, 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] warning: unused variable: `c`
[INFO] [stdout]   --> src/playground/calculator.rs:74:13
[INFO] [stdout]    |
[INFO] [stdout] 74 |         let c = self.next_token();
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[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 `rust_playground` (bin "rust_playground") due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "e070744f082138ea5d84a63b8e89f89753c253387d6fa11594f9aa407e99b914", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e070744f082138ea5d84a63b8e89f89753c253387d6fa11594f9aa407e99b914", kill_on_drop: false }`
[INFO] [stdout] e070744f082138ea5d84a63b8e89f89753c253387d6fa11594f9aa407e99b914