[INFO] updating cached repository GrahamClark/collections-exercises-rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/GrahamClark/collections-exercises-rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/GrahamClark/collections-exercises-rust" "work/ex/beta-1.38-1/sources/1.37.0/gh/GrahamClark/collections-exercises-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/GrahamClark/collections-exercises-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/GrahamClark/collections-exercises-rust" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/GrahamClark/collections-exercises-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/GrahamClark/collections-exercises-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 07217f7bbfeea46e91534db8ae932919ea060e90
[INFO] sha for GitHub repo GrahamClark/collections-exercises-rust: 07217f7bbfeea46e91534db8ae932919ea060e90
[INFO] validating manifest of GrahamClark/collections-exercises-rust 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 GrahamClark/collections-exercises-rust 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 GrahamClark/collections-exercises-rust
[INFO] finished frobbing GrahamClark/collections-exercises-rust
[INFO] frobbed toml for GrahamClark/collections-exercises-rust written to work/ex/beta-1.38-1/sources/1.37.0/gh/GrahamClark/collections-exercises-rust/Cargo.toml
[INFO] started frobbing GrahamClark/collections-exercises-rust
[INFO] finished frobbing GrahamClark/collections-exercises-rust
[INFO] frobbed toml for GrahamClark/collections-exercises-rust written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/GrahamClark/collections-exercises-rust/Cargo.toml
[INFO] crate GrahamClark/collections-exercises-rust 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 GrahamClark/collections-exercises-rust 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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/GrahamClark/collections-exercises-rust:/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] 4246e6f8132354484107eb57debaad29300b7e09abe8e7343e02d76c5ede4997
[INFO] running `"docker" "start" "-a" "4246e6f8132354484107eb57debaad29300b7e09abe8e7343e02d76c5ede4997"`
[INFO] [stderr]    Compiling collections_exercises v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.64s
[INFO] running `"docker" "inspect" "4246e6f8132354484107eb57debaad29300b7e09abe8e7343e02d76c5ede4997"`
[INFO] running `"docker" "rm" "-f" "4246e6f8132354484107eb57debaad29300b7e09abe8e7343e02d76c5ede4997"`
[INFO] [stdout] 4246e6f8132354484107eb57debaad29300b7e09abe8e7343e02d76c5ede4997
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/GrahamClark/collections-exercises-rust:/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" "test" "--frozen" "--no-run"`
[INFO] [stdout] 22e6adfc3c2a81db5ef6eb119a91a73e8edd517521c087b8cc7b6b7155670a0a
[INFO] running `"docker" "start" "-a" "22e6adfc3c2a81db5ef6eb119a91a73e8edd517521c087b8cc7b6b7155670a0a"`
[INFO] [stderr]    Compiling collections_exercises v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.86s
[INFO] running `"docker" "inspect" "22e6adfc3c2a81db5ef6eb119a91a73e8edd517521c087b8cc7b6b7155670a0a"`
[INFO] running `"docker" "rm" "-f" "22e6adfc3c2a81db5ef6eb119a91a73e8edd517521c087b8cc7b6b7155670a0a"`
[INFO] [stdout] 22e6adfc3c2a81db5ef6eb119a91a73e8edd517521c087b8cc7b6b7155670a0a
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/GrahamClark/collections-exercises-rust:/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" "test" "--frozen"`
[INFO] [stdout] 6fd9bd2d99cb0c4c1f3823e60146e609a167e1f60509d82615e0cd9fe89be7f2
[INFO] running `"docker" "start" "-a" "6fd9bd2d99cb0c4c1f3823e60146e609a167e1f60509d82615e0cd9fe89be7f2"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/collections_exercises-fff04dcaff816ac9
[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] [stderr]      Running /opt/crater/target/debug/deps/collections_exercises-6b68eaf309dda5d0
[INFO] [stderr]    Doc-tests collections_exercises
[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] [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" "6fd9bd2d99cb0c4c1f3823e60146e609a167e1f60509d82615e0cd9fe89be7f2"`
[INFO] running `"docker" "rm" "-f" "6fd9bd2d99cb0c4c1f3823e60146e609a167e1f60509d82615e0cd9fe89be7f2"`
[INFO] [stdout] 6fd9bd2d99cb0c4c1f3823e60146e609a167e1f60509d82615e0cd9fe89be7f2