[INFO] updating cached repository nekokuro0xf/workerpool
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/nekokuro0xf/workerpool
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/nekokuro0xf/workerpool" "work/ex/beta-1.38-1/sources/1.37.0/gh/nekokuro0xf/workerpool"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/nekokuro0xf/workerpool'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/nekokuro0xf/workerpool" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nekokuro0xf/workerpool"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nekokuro0xf/workerpool'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] ab5f095836f1c52147f6192e65831325f54272c5
[INFO] sha for GitHub repo nekokuro0xf/workerpool: ab5f095836f1c52147f6192e65831325f54272c5
[INFO] validating manifest of nekokuro0xf/workerpool on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of nekokuro0xf/workerpool on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing nekokuro0xf/workerpool
[INFO] finished frobbing nekokuro0xf/workerpool
[INFO] frobbed toml for nekokuro0xf/workerpool written to work/ex/beta-1.38-1/sources/1.37.0/gh/nekokuro0xf/workerpool/Cargo.toml
[INFO] started frobbing nekokuro0xf/workerpool
[INFO] finished frobbing nekokuro0xf/workerpool
[INFO] frobbed toml for nekokuro0xf/workerpool written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nekokuro0xf/workerpool/Cargo.toml
[INFO] crate nekokuro0xf/workerpool already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing nekokuro0xf/workerpool against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-2/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/nekokuro0xf/workerpool:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] dd9a875310ec5edaec90a06a783cf99c34a69e59b0235a17dcd4e61c0fa50edb
[INFO] running `"docker" "start" "-a" "dd9a875310ec5edaec90a06a783cf99c34a69e59b0235a17dcd4e61c0fa50edb"`
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.44
[INFO] [stderr]    Compiling bumpalo v2.4.1
[INFO] [stderr]    Compiling wasm-bindgen v0.2.44
[INFO] [stderr]    Compiling base-x v0.2.4
[INFO] [stderr]    Compiling backtrace v0.3.17
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]    Compiling weedle v0.8.0
[INFO] [stderr]    Compiling env_logger v0.6.1
[INFO] [stderr]    Compiling stdweb-derive v0.5.1
[INFO] [stderr]    Compiling stdweb-internal-macros v0.2.7
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.44
[INFO] [stderr]    Compiling stdweb v0.4.17
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.44
[INFO] [stderr]    Compiling wasm-bindgen-webidl v0.2.44
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.44
[INFO] [stderr]    Compiling js-sys v0.3.21
[INFO] [stderr]    Compiling web-sys v0.3.21
[INFO] [stderr]    Compiling rust_wasm_workerpool v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `std::ops::Try`)
[INFO] [stderr]   --> src/main.rs:27:24
[INFO] [stderr]    |
[INFO] [stderr] 27 |     let mut  worker  = Worker::new("./worker.js")?;
[INFO] [stderr]    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: the trait `std::ops::Try` is not implemented for `()`
[INFO] [stderr]    = note: required by `std::ops::Try::from_error`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0277`.
[INFO] [stderr] error: Could not compile `rust_wasm_workerpool`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "dd9a875310ec5edaec90a06a783cf99c34a69e59b0235a17dcd4e61c0fa50edb"`
[INFO] running `"docker" "rm" "-f" "dd9a875310ec5edaec90a06a783cf99c34a69e59b0235a17dcd4e61c0fa50edb"`
[INFO] [stdout] dd9a875310ec5edaec90a06a783cf99c34a69e59b0235a17dcd4e61c0fa50edb