[INFO] updating cached repository howeih/Day-41-Union-Find
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/howeih/Day-41-Union-Find
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/howeih/Day-41-Union-Find" "work/ex/beta-1.37-6/sources/1.36.0/gh/howeih/Day-41-Union-Find"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/howeih/Day-41-Union-Find'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/howeih/Day-41-Union-Find" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/howeih/Day-41-Union-Find"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/howeih/Day-41-Union-Find'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 32bc36cc71e78ad0217c3dc428395f49b9f0fe15
[INFO] sha for GitHub repo howeih/Day-41-Union-Find: 32bc36cc71e78ad0217c3dc428395f49b9f0fe15
[INFO] validating manifest of howeih/Day-41-Union-Find on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of howeih/Day-41-Union-Find on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing howeih/Day-41-Union-Find
[INFO] finished frobbing howeih/Day-41-Union-Find
[INFO] frobbed toml for howeih/Day-41-Union-Find written to work/ex/beta-1.37-6/sources/1.36.0/gh/howeih/Day-41-Union-Find/Cargo.toml
[INFO] started frobbing howeih/Day-41-Union-Find
[INFO] finished frobbing howeih/Day-41-Union-Find
[INFO] frobbed toml for howeih/Day-41-Union-Find written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/howeih/Day-41-Union-Find/Cargo.toml
[INFO] crate howeih/Day-41-Union-Find already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing howeih/Day-41-Union-Find against 1.36.0 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-2/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/howeih/Day-41-Union-Find:/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" "+1.36.0" "build" "--frozen"`
[INFO] [stdout] 1fe091e04fa4ecffa38049fc03d36f7f2709a900d103ae5ada714ea1cd2b333b
[INFO] running `"docker" "start" "-a" "1fe091e04fa4ecffa38049fc03d36f7f2709a900d103ae5ada714ea1cd2b333b"`
[INFO] [stderr]    Compiling union_find v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std::iter::Iterator`
[INFO] [stderr]  --> src/main.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::iter::Iterator;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.47s
[INFO] running `"docker" "inspect" "1fe091e04fa4ecffa38049fc03d36f7f2709a900d103ae5ada714ea1cd2b333b"`
[INFO] running `"docker" "rm" "-f" "1fe091e04fa4ecffa38049fc03d36f7f2709a900d103ae5ada714ea1cd2b333b"`
[INFO] [stdout] 1fe091e04fa4ecffa38049fc03d36f7f2709a900d103ae5ada714ea1cd2b333b
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-2/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/howeih/Day-41-Union-Find:/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" "+1.36.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] 5bb963bb39d6ec2238ce79711ad84f51aa52d7665365e08d3b5c8c189e7cd250
[INFO] running `"docker" "start" "-a" "5bb963bb39d6ec2238ce79711ad84f51aa52d7665365e08d3b5c8c189e7cd250"`
[INFO] [stderr]    Compiling union_find v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std::iter::Iterator`
[INFO] [stderr]  --> src/main.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::iter::Iterator;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.38s
[INFO] running `"docker" "inspect" "5bb963bb39d6ec2238ce79711ad84f51aa52d7665365e08d3b5c8c189e7cd250"`
[INFO] running `"docker" "rm" "-f" "5bb963bb39d6ec2238ce79711ad84f51aa52d7665365e08d3b5c8c189e7cd250"`
[INFO] [stdout] 5bb963bb39d6ec2238ce79711ad84f51aa52d7665365e08d3b5c8c189e7cd250
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-2/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/howeih/Day-41-Union-Find:/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" "+1.36.0" "test" "--frozen"`
[INFO] [stdout] 824f92468f72b2cd43e81ff9cf86aad81bba18653dddbf9268c534995fdc391f
[INFO] running `"docker" "start" "-a" "824f92468f72b2cd43e81ff9cf86aad81bba18653dddbf9268c534995fdc391f"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/union_find-2797b34a9852aba3
[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" "824f92468f72b2cd43e81ff9cf86aad81bba18653dddbf9268c534995fdc391f"`
[INFO] running `"docker" "rm" "-f" "824f92468f72b2cd43e81ff9cf86aad81bba18653dddbf9268c534995fdc391f"`
[INFO] [stdout] 824f92468f72b2cd43e81ff9cf86aad81bba18653dddbf9268c534995fdc391f