[INFO] updating cached repository PhilipDaniels/word_chains
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/PhilipDaniels/word_chains
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/PhilipDaniels/word_chains" "work/ex/beta-1.37-6/sources/1.36.0/gh/PhilipDaniels/word_chains"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/PhilipDaniels/word_chains'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/PhilipDaniels/word_chains" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/PhilipDaniels/word_chains"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/PhilipDaniels/word_chains'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] bf9430e6e6619f1988c7fe4bd4d6af853559eb35
[INFO] sha for GitHub repo PhilipDaniels/word_chains: bf9430e6e6619f1988c7fe4bd4d6af853559eb35
[INFO] validating manifest of PhilipDaniels/word_chains 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 PhilipDaniels/word_chains 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 PhilipDaniels/word_chains
[INFO] finished frobbing PhilipDaniels/word_chains
[INFO] frobbed toml for PhilipDaniels/word_chains written to work/ex/beta-1.37-6/sources/1.36.0/gh/PhilipDaniels/word_chains/Cargo.toml
[INFO] started frobbing PhilipDaniels/word_chains
[INFO] finished frobbing PhilipDaniels/word_chains
[INFO] frobbed toml for PhilipDaniels/word_chains written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/PhilipDaniels/word_chains/Cargo.toml
[INFO] crate PhilipDaniels/word_chains 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 PhilipDaniels/word_chains 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-5/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/PhilipDaniels/word_chains:/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] 5b88f0997f57769d28590146ad888d872db2bfef731eb7dec903917a6f98543a
[INFO] running `"docker" "start" "-a" "5b88f0997f57769d28590146ad888d872db2bfef731eb7dec903917a6f98543a"`
[INFO] [stderr]    Compiling syn v0.12.14
[INFO] [stderr]    Compiling structopt-derive v0.2.5
[INFO] [stderr]    Compiling structopt v0.2.5
[INFO] [stderr]    Compiling word_chains v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused `#[macro_use]` import
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #[macro_use] extern crate structopt;
[INFO] [stderr]   | ^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `g`
[INFO] [stderr]   --> src/letter_differences.rs:36:13
[INFO] [stderr]    |
[INFO] [stderr] 36 |         let g = make_graph(&rwords_for_table);
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_g`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/dictionary.rs:23:13
[INFO] [stderr]    |
[INFO] [stderr] 23 |         let mut rdr = io::BufReader::new(file);
[INFO] [stderr]    |             ----^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `word`
[INFO] [stderr]  --> src/graph.rs:4:5
[INFO] [stderr]   |
[INFO] [stderr] 4 |     word: &'word String,
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `word`
[INFO] [stderr]   --> src/graph.rs:18:5
[INFO] [stderr]    |
[INFO] [stderr] 18 |     fn word(&self) -> &String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 14.05s
[INFO] running `"docker" "inspect" "5b88f0997f57769d28590146ad888d872db2bfef731eb7dec903917a6f98543a"`
[INFO] running `"docker" "rm" "-f" "5b88f0997f57769d28590146ad888d872db2bfef731eb7dec903917a6f98543a"`
[INFO] [stdout] 5b88f0997f57769d28590146ad888d872db2bfef731eb7dec903917a6f98543a
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-5/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/PhilipDaniels/word_chains:/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] d42cf11f958b4c3b51d433e2d80e88dcde4dfb6e4817c6b0d3d2bcf0c8056462
[INFO] running `"docker" "start" "-a" "d42cf11f958b4c3b51d433e2d80e88dcde4dfb6e4817c6b0d3d2bcf0c8056462"`
[INFO] [stderr]    Compiling word_chains v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused `#[macro_use]` import
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #[macro_use] extern crate structopt;
[INFO] [stderr]   | ^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `g`
[INFO] [stderr]   --> src/letter_differences.rs:36:13
[INFO] [stderr]    |
[INFO] [stderr] 36 |         let g = make_graph(&rwords_for_table);
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_g`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/dictionary.rs:23:13
[INFO] [stderr]    |
[INFO] [stderr] 23 |         let mut rdr = io::BufReader::new(file);
[INFO] [stderr]    |             ----^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `word`
[INFO] [stderr]  --> src/graph.rs:4:5
[INFO] [stderr]   |
[INFO] [stderr] 4 |     word: &'word String,
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `word`
[INFO] [stderr]   --> src/graph.rs:18:5
[INFO] [stderr]    |
[INFO] [stderr] 18 |     fn word(&self) -> &String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.26s
[INFO] running `"docker" "inspect" "d42cf11f958b4c3b51d433e2d80e88dcde4dfb6e4817c6b0d3d2bcf0c8056462"`
[INFO] running `"docker" "rm" "-f" "d42cf11f958b4c3b51d433e2d80e88dcde4dfb6e4817c6b0d3d2bcf0c8056462"`
[INFO] [stdout] d42cf11f958b4c3b51d433e2d80e88dcde4dfb6e4817c6b0d3d2bcf0c8056462
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-5/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/PhilipDaniels/word_chains:/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] cf76de19b7073b4b72d2b70b7e3152b0a7918b098f1666c5346561ab1e4ea5a1
[INFO] running `"docker" "start" "-a" "cf76de19b7073b4b72d2b70b7e3152b0a7918b098f1666c5346561ab1e4ea5a1"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/word_chains-885eb4fce93882ca
[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" "cf76de19b7073b4b72d2b70b7e3152b0a7918b098f1666c5346561ab1e4ea5a1"`
[INFO] running `"docker" "rm" "-f" "cf76de19b7073b4b72d2b70b7e3152b0a7918b098f1666c5346561ab1e4ea5a1"`
[INFO] [stdout] cf76de19b7073b4b72d2b70b7e3152b0a7918b098f1666c5346561ab1e4ea5a1