[INFO] updating cached repository Mahtiah/maze_generator
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Mahtiah/maze_generator
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Mahtiah/maze_generator" "work/ex/beta-1.38-1/sources/1.37.0/gh/Mahtiah/maze_generator"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Mahtiah/maze_generator'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Mahtiah/maze_generator" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mahtiah/maze_generator"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mahtiah/maze_generator'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 06297a5537a3fba87f8feaa56ef42798eb932590
[INFO] sha for GitHub repo Mahtiah/maze_generator: 06297a5537a3fba87f8feaa56ef42798eb932590
[INFO] validating manifest of Mahtiah/maze_generator 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 Mahtiah/maze_generator 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 Mahtiah/maze_generator
[INFO] finished frobbing Mahtiah/maze_generator
[INFO] frobbed toml for Mahtiah/maze_generator written to work/ex/beta-1.38-1/sources/1.37.0/gh/Mahtiah/maze_generator/Cargo.toml
[INFO] started frobbing Mahtiah/maze_generator
[INFO] finished frobbing Mahtiah/maze_generator
[INFO] frobbed toml for Mahtiah/maze_generator written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mahtiah/maze_generator/Cargo.toml
[INFO] crate Mahtiah/maze_generator 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] [stderr] error: the lock file /mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/Mahtiah/maze_generator/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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 Mahtiah/maze_generator 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-0/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/Mahtiah/maze_generator:/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] 2cf1d283aa1800ce04a00fce016efc5b9d2924e822fe6188e4d3afe3358ec779
[INFO] running `"docker" "start" "-a" "2cf1d283aa1800ce04a00fce016efc5b9d2924e822fe6188e4d3afe3358ec779"`
[INFO] [stderr]    Compiling maze_generator v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:10:9
[INFO] [stderr]    |
[INFO] [stderr] 10 |     for x in 0..maze.width()
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.62s
[INFO] running `"docker" "inspect" "2cf1d283aa1800ce04a00fce016efc5b9d2924e822fe6188e4d3afe3358ec779"`
[INFO] running `"docker" "rm" "-f" "2cf1d283aa1800ce04a00fce016efc5b9d2924e822fe6188e4d3afe3358ec779"`
[INFO] [stdout] 2cf1d283aa1800ce04a00fce016efc5b9d2924e822fe6188e4d3afe3358ec779
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/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/Mahtiah/maze_generator:/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" "test" "--frozen" "--no-run"`
[INFO] [stdout] be6dd02acfb5224cb8f29204bab2de8db98e429eec69988cddf246e5cc5362f9
[INFO] running `"docker" "start" "-a" "be6dd02acfb5224cb8f29204bab2de8db98e429eec69988cddf246e5cc5362f9"`
[INFO] [stderr]    Compiling maze_generator v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:10:9
[INFO] [stderr]    |
[INFO] [stderr] 10 |     for x in 0..maze.width()
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.46s
[INFO] running `"docker" "inspect" "be6dd02acfb5224cb8f29204bab2de8db98e429eec69988cddf246e5cc5362f9"`
[INFO] running `"docker" "rm" "-f" "be6dd02acfb5224cb8f29204bab2de8db98e429eec69988cddf246e5cc5362f9"`
[INFO] [stdout] be6dd02acfb5224cb8f29204bab2de8db98e429eec69988cddf246e5cc5362f9
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/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/Mahtiah/maze_generator:/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" "test" "--frozen"`
[INFO] [stdout] f8bd99cbfdce863cd906ea3839d6a52db5d68456d795f1a5f3731eea76d8ceb9
[INFO] running `"docker" "start" "-a" "f8bd99cbfdce863cd906ea3839d6a52db5d68456d795f1a5f3731eea76d8ceb9"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/maze_generator-c39f4f6d73cd5657
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "f8bd99cbfdce863cd906ea3839d6a52db5d68456d795f1a5f3731eea76d8ceb9"`
[INFO] running `"docker" "rm" "-f" "f8bd99cbfdce863cd906ea3839d6a52db5d68456d795f1a5f3731eea76d8ceb9"`
[INFO] [stdout] f8bd99cbfdce863cd906ea3839d6a52db5d68456d795f1a5f3731eea76d8ceb9