[INFO] updating cached repository tercen/rustson
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/tercen/rustson
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/tercen/rustson" "work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/tercen/rustson"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/tercen/rustson'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/tercen/rustson" "work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/tercen/rustson"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/tercen/rustson'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 0f8395bd0d024c80031eb4ab3c0154fcb7b9d99f
[INFO] sha for GitHub repo tercen/rustson: 0f8395bd0d024c80031eb4ab3c0154fcb7b9d99f
[INFO] validating manifest of tercen/rustson on toolchain master#f66e4697ae286985ddefc53c3a047614568458bb
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of tercen/rustson on toolchain try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c3b22200e6f5b70eb1f99ae6944d989ae17a458a-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing tercen/rustson
[INFO] finished frobbing tercen/rustson
[INFO] frobbed toml for tercen/rustson written to work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/tercen/rustson/Cargo.toml
[INFO] started frobbing tercen/rustson
[INFO] finished frobbing tercen/rustson
[INFO] frobbed toml for tercen/rustson written to work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/tercen/rustson/Cargo.toml
[INFO] crate tercen/rustson has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c3b22200e6f5b70eb1f99ae6944d989ae17a458a-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking tercen/rustson against master#f66e4697ae286985ddefc53c3a047614568458bb for pr-58592
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-58592/worker-4/master#f66e4697ae286985ddefc53c3a047614568458bb:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/tercen/rustson:/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=forbid" "-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" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] a4d6adba112e404fe1fc79e18e504e23b3221d0e0a9b108018f42330f756d52d
[INFO] running `"docker" "start" "-a" "a4d6adba112e404fe1fc79e18e504e23b3221d0e0a9b108018f42330f756d52d"`
[INFO] [stderr]     Checking rustson v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std::fs::File`
[INFO] [stderr]    --> src/lib.rs:456:9
[INFO] [stderr]     |
[INFO] [stderr] 456 |     use std::fs::File;
[INFO] [stderr]     |         ^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::io::prelude::*`
[INFO] [stderr]    --> src/lib.rs:457:9
[INFO] [stderr]     |
[INFO] [stderr] 457 |     use std::io::prelude::*;
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:133:17
[INFO] [stderr]     |
[INFO] [stderr] 133 |                 add_object(v, buf);
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_must_use)] on by default
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:133:17
[INFO] [stderr]     |
[INFO] [stderr] 133 |                 add_object(v, buf);
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_must_use)] on by default
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.67s
[INFO] running `"docker" "inspect" "a4d6adba112e404fe1fc79e18e504e23b3221d0e0a9b108018f42330f756d52d"`
[INFO] running `"docker" "rm" "-f" "a4d6adba112e404fe1fc79e18e504e23b3221d0e0a9b108018f42330f756d52d"`
[INFO] [stdout] a4d6adba112e404fe1fc79e18e504e23b3221d0e0a9b108018f42330f756d52d