[INFO] crate backtracking_iterator 0.4.4 is already in cache
[INFO] extracting crate backtracking_iterator 0.4.4 into work/ex/beta-1.38-1/sources/1.37.0/reg/backtracking_iterator/0.4.4
[INFO] extracting crate backtracking_iterator 0.4.4 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/backtracking_iterator/0.4.4
[INFO] validating manifest of backtracking_iterator-0.4.4 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 backtracking_iterator-0.4.4 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 backtracking_iterator-0.4.4
[INFO] finished frobbing backtracking_iterator-0.4.4
[INFO] frobbed toml for backtracking_iterator-0.4.4 written to work/ex/beta-1.38-1/sources/1.37.0/reg/backtracking_iterator/0.4.4/Cargo.toml
[INFO] started frobbing backtracking_iterator-0.4.4
[INFO] finished frobbing backtracking_iterator-0.4.4
[INFO] frobbed toml for backtracking_iterator-0.4.4 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/backtracking_iterator/0.4.4/Cargo.toml
[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 backtracking_iterator-0.4.4 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-2/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/backtracking_iterator/0.4.4:/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] 3f574903e3ca923f2e9239464092686eb422ee74066ac89cbe3e2e405cfb779a
[INFO] running `"docker" "start" "-a" "3f574903e3ca923f2e9239464092686eb422ee74066ac89cbe3e2e405cfb779a"`
[INFO] [stderr]    Compiling backtracking_iterator v0.4.4 (/opt/crater/workdir)
[INFO] [stderr] warning: the item `Backtracking` is imported redundantly
[INFO] [stderr]   --> src/copying.rs:38:17
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Backtracking` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 38 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                 ^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: the item `Progressing` is imported redundantly
[INFO] [stderr]   --> src/copying.rs:38:31
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Progressing` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 38 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                               ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the item `Backtracking` is imported redundantly
[INFO] [stderr]   --> src/referencing.rs:57:17
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Backtracking` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 57 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                 ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the item `Progressing` is imported redundantly
[INFO] [stderr]   --> src/referencing.rs:57:31
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Progressing` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 57 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                               ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `BacktrackingState`
[INFO] [stderr]   --> src/concurrent.rs:22:13
[INFO] [stderr]    |
[INFO] [stderr] 22 | use super::{BacktrackingState, BacktrackingIterator};
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Backtracking`, `Progressing`
[INFO] [stderr]   --> src/concurrent.rs:72:17
[INFO] [stderr]    |
[INFO] [stderr] 72 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                 ^^^^^^^^^^^^  ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Backtracking`, `Progressing`
[INFO] [stderr]    --> src/concurrent.rs:140:17
[INFO] [stderr]     |
[INFO] [stderr] 140 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]     |                 ^^^^^^^^^^^^  ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.48s
[INFO] running `"docker" "inspect" "3f574903e3ca923f2e9239464092686eb422ee74066ac89cbe3e2e405cfb779a"`
[INFO] running `"docker" "rm" "-f" "3f574903e3ca923f2e9239464092686eb422ee74066ac89cbe3e2e405cfb779a"`
[INFO] [stdout] 3f574903e3ca923f2e9239464092686eb422ee74066ac89cbe3e2e405cfb779a
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-2/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/backtracking_iterator/0.4.4:/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] 0e2163e3ca1d44dc948f63b942c1ad847669ae4bc724068a17cb3933c8bcd04d
[INFO] running `"docker" "start" "-a" "0e2163e3ca1d44dc948f63b942c1ad847669ae4bc724068a17cb3933c8bcd04d"`
[INFO] [stderr]    Compiling backtracking_iterator v0.4.4 (/opt/crater/workdir)
[INFO] [stderr] warning: the item `Backtracking` is imported redundantly
[INFO] [stderr]   --> src/copying.rs:38:17
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Backtracking` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 38 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                 ^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: the item `Progressing` is imported redundantly
[INFO] [stderr]   --> src/copying.rs:38:31
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Progressing` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 38 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                               ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the item `Backtracking` is imported redundantly
[INFO] [stderr]   --> src/referencing.rs:57:17
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Backtracking` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 57 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                 ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the item `Progressing` is imported redundantly
[INFO] [stderr]   --> src/referencing.rs:57:31
[INFO] [stderr]    |
[INFO] [stderr] 23 | use super::BacktrackingState::*;
[INFO] [stderr]    |     --------------------------- the item `Progressing` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 57 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                               ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `BacktrackingState`
[INFO] [stderr]   --> src/concurrent.rs:22:13
[INFO] [stderr]    |
[INFO] [stderr] 22 | use super::{BacktrackingState, BacktrackingIterator};
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Backtracking`, `Progressing`
[INFO] [stderr]   --> src/concurrent.rs:72:17
[INFO] [stderr]    |
[INFO] [stderr] 72 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]    |                 ^^^^^^^^^^^^  ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Backtracking`, `Progressing`
[INFO] [stderr]    --> src/concurrent.rs:140:17
[INFO] [stderr]     |
[INFO] [stderr] 140 |     use crate::{Backtracking, Progressing};
[INFO] [stderr]     |                 ^^^^^^^^^^^^  ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.30s
[INFO] running `"docker" "inspect" "0e2163e3ca1d44dc948f63b942c1ad847669ae4bc724068a17cb3933c8bcd04d"`
[INFO] running `"docker" "rm" "-f" "0e2163e3ca1d44dc948f63b942c1ad847669ae4bc724068a17cb3933c8bcd04d"`
[INFO] [stdout] 0e2163e3ca1d44dc948f63b942c1ad847669ae4bc724068a17cb3933c8bcd04d
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-2/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/backtracking_iterator/0.4.4:/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] df472ba7b7c8f9b5553676bfd0983fdcb9d93c7db3204d555f8794e3f1f7993d
[INFO] running `"docker" "start" "-a" "df472ba7b7c8f9b5553676bfd0983fdcb9d93c7db3204d555f8794e3f1f7993d"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.04s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/backtracking_iterator-4a0e8d6db52a2764
[INFO] [stdout] 
[INFO] [stdout] running 5 tests
[INFO] [stdout] test tests::basic_test ... ok
[INFO] [stdout] test tests::backwalk_test ... ok
[INFO] [stdout] test concurrent::tests::many_iter_test ... ok
[INFO] [stdout] test concurrent::tests::many_iter_clone_test ... ok
[INFO] [stdout] test concurrent::tests::dont_need_clone_test ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 5 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests backtracking_iterator
[INFO] [stdout] 
[INFO] [stdout] running 7 tests
[INFO] [stdout] test src/traits.rs - traits::BacktrackingIterator::peek (line 121) ... ok
[INFO] [stdout] test src/record.rs - record::BacktrackingRecorder<Iter>::drain_history (line 53) ... ok
[INFO] [stdout] test src/traits.rs - traits::Walkbackable::walk_back (line 155) ... ok
[INFO] [stdout] test src/traits.rs - traits::Record::forget (line 36) ... ok
[INFO] [stdout] test src/record.rs - record::BacktrackingRecorder<Iter>::into_iter (line 83) ... ok
[INFO] [stdout] test src/traits.rs - traits::BacktrackingIterator::start_again (line 101) ... ok
[INFO] [stdout] test src/traits.rs - traits::BacktrackingIterator::backtrack (line 77) ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 7 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "df472ba7b7c8f9b5553676bfd0983fdcb9d93c7db3204d555f8794e3f1f7993d"`
[INFO] running `"docker" "rm" "-f" "df472ba7b7c8f9b5553676bfd0983fdcb9d93c7db3204d555f8794e3f1f7993d"`
[INFO] [stdout] df472ba7b7c8f9b5553676bfd0983fdcb9d93c7db3204d555f8794e3f1f7993d