[INFO] updating cached repository bpk-t/rust_practice
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/bpk-t/rust_practice
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/bpk-t/rust_practice" "work/ex/beta-1.38-1/sources/1.37.0/gh/bpk-t/rust_practice"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/bpk-t/rust_practice'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/bpk-t/rust_practice" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bpk-t/rust_practice"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bpk-t/rust_practice'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1df7873e9a168056f85a8118ad00cb22173bc000
[INFO] sha for GitHub repo bpk-t/rust_practice: 1df7873e9a168056f85a8118ad00cb22173bc000
[INFO] validating manifest of bpk-t/rust_practice 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 bpk-t/rust_practice 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 bpk-t/rust_practice
[INFO] finished frobbing bpk-t/rust_practice
[INFO] frobbed toml for bpk-t/rust_practice written to work/ex/beta-1.38-1/sources/1.37.0/gh/bpk-t/rust_practice/Cargo.toml
[INFO] started frobbing bpk-t/rust_practice
[INFO] finished frobbing bpk-t/rust_practice
[INFO] frobbed toml for bpk-t/rust_practice written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bpk-t/rust_practice/Cargo.toml
[INFO] crate bpk-t/rust_practice 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] testing bpk-t/rust_practice against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bpk-t/rust_practice:/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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 1784b1598df02d7fb04fe7d6f4e55aa1816d23eaaee1af2f3bcb4cc6723076a0
[INFO] running `"docker" "start" "-a" "1784b1598df02d7fb04fe7d6f4e55aa1816d23eaaee1af2f3bcb4cc6723076a0"`
[INFO] [stderr]    Compiling rust_practice v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0601]: `main` function not found in crate `lang_spec`
[INFO] [stderr]   |
[INFO] [stderr]   = note: consider adding a `main` function to `src/bin/lang_spec.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: Could not compile `rust_practice`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "1784b1598df02d7fb04fe7d6f4e55aa1816d23eaaee1af2f3bcb4cc6723076a0"`
[INFO] running `"docker" "rm" "-f" "1784b1598df02d7fb04fe7d6f4e55aa1816d23eaaee1af2f3bcb4cc6723076a0"`
[INFO] [stdout] 1784b1598df02d7fb04fe7d6f4e55aa1816d23eaaee1af2f3bcb4cc6723076a0