[INFO] updating cached repository thara/rust_playground
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/thara/rust_playground
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/thara/rust_playground" "work/ex/beta-1.38-1/sources/1.37.0/gh/thara/rust_playground"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/thara/rust_playground'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/thara/rust_playground" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/thara/rust_playground"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/thara/rust_playground'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 37641e434355701643f834ea5bb0980992d6cae4
[INFO] sha for GitHub repo thara/rust_playground: 37641e434355701643f834ea5bb0980992d6cae4
[INFO] validating manifest of thara/rust_playground 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 thara/rust_playground 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 thara/rust_playground
[INFO] finished frobbing thara/rust_playground
[INFO] frobbed toml for thara/rust_playground written to work/ex/beta-1.38-1/sources/1.37.0/gh/thara/rust_playground/Cargo.toml
[INFO] started frobbing thara/rust_playground
[INFO] finished frobbing thara/rust_playground
[INFO] frobbed toml for thara/rust_playground written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/thara/rust_playground/Cargo.toml
[INFO] crate thara/rust_playground 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 thara/rust_playground 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-5/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/thara/rust_playground:/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] c309e3c918cf28622fb3990952e17f6bbf8de978982f79cc1ed5304ad6222bfe
[INFO] running `"docker" "start" "-a" "c309e3c918cf28622fb3990952e17f6bbf8de978982f79cc1ed5304ad6222bfe"`
[INFO] [stderr]    Compiling rust_playground v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0583]: file not found for module `linked_list`
[INFO] [stderr]  --> src/lib.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | mod linked_list;
[INFO] [stderr]   |     ^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = help: name the file either linked_list.rs or linked_list/mod.rs inside the directory "src"
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0583`.
[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" "c309e3c918cf28622fb3990952e17f6bbf8de978982f79cc1ed5304ad6222bfe"`
[INFO] running `"docker" "rm" "-f" "c309e3c918cf28622fb3990952e17f6bbf8de978982f79cc1ed5304ad6222bfe"`
[INFO] [stdout] c309e3c918cf28622fb3990952e17f6bbf8de978982f79cc1ed5304ad6222bfe