[INFO] crate tail 0.3.0 is already in cache
[INFO] extracting crate tail 0.3.0 into work/ex/beta-1.38-1/sources/1.37.0/reg/tail/0.3.0
[INFO] extracting crate tail 0.3.0 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tail/0.3.0
[INFO] validating manifest of tail-0.3.0 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 tail-0.3.0 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 tail-0.3.0
[INFO] finished frobbing tail-0.3.0
[INFO] frobbed toml for tail-0.3.0 written to work/ex/beta-1.38-1/sources/1.37.0/reg/tail/0.3.0/Cargo.toml
[INFO] started frobbing tail-0.3.0
[INFO] finished frobbing tail-0.3.0
[INFO] frobbed toml for tail-0.3.0 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tail/0.3.0/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 tail-0.3.0 against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-2/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tail/0.3.0:/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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 0f40361d3b773e84a2e512986b8b0e36090f52d2b043e17ef1e12d221aa724a9
[INFO] running `"docker" "start" "-a" "0f40361d3b773e84a2e512986b8b0e36090f52d2b043e17ef1e12d221aa724a9"`
[INFO] [stderr]    Compiling inotify v0.5.1
[INFO] [stderr]    Compiling tail v0.3.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:88:13
[INFO] [stderr]    |
[INFO] [stderr] 88 |         let mut wd = watcher.add_watch(Path::new(&file_name), WatchMask::MODIFY)
[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: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:90:13
[INFO] [stderr]    |
[INFO] [stderr] 90 |         let mut fd = File::open(&file_name)
[INFO] [stderr]    |             ----^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.66s
[INFO] running `"docker" "inspect" "0f40361d3b773e84a2e512986b8b0e36090f52d2b043e17ef1e12d221aa724a9"`
[INFO] running `"docker" "rm" "-f" "0f40361d3b773e84a2e512986b8b0e36090f52d2b043e17ef1e12d221aa724a9"`
[INFO] [stdout] 0f40361d3b773e84a2e512986b8b0e36090f52d2b043e17ef1e12d221aa724a9
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-2/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tail/0.3.0:/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" "+beta-2019-08-13" "test" "--frozen" "--no-run"`
[INFO] [stdout] a2e0e21d1bae61f43ada346636603aa6b013869421042601fc74fc432b36c2c6
[INFO] running `"docker" "start" "-a" "a2e0e21d1bae61f43ada346636603aa6b013869421042601fc74fc432b36c2c6"`
[INFO] [stderr]    Compiling tail v0.3.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:88:13
[INFO] [stderr]    |
[INFO] [stderr] 88 |         let mut wd = watcher.add_watch(Path::new(&file_name), WatchMask::MODIFY)
[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: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:90:13
[INFO] [stderr]    |
[INFO] [stderr] 90 |         let mut fd = File::open(&file_name)
[INFO] [stderr]    |             ----^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.20s
[INFO] running `"docker" "inspect" "a2e0e21d1bae61f43ada346636603aa6b013869421042601fc74fc432b36c2c6"`
[INFO] running `"docker" "rm" "-f" "a2e0e21d1bae61f43ada346636603aa6b013869421042601fc74fc432b36c2c6"`
[INFO] [stdout] a2e0e21d1bae61f43ada346636603aa6b013869421042601fc74fc432b36c2c6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-2/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tail/0.3.0:/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" "+beta-2019-08-13" "test" "--frozen"`
[INFO] [stdout] 83df0ccf11a3057621c0a9e71d91c18065492c2708985f2b93f98d1c81698653
[INFO] running `"docker" "start" "-a" "83df0ccf11a3057621c0a9e71d91c18065492c2708985f2b93f98d1c81698653"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/tail-b311f492ab661bbe
[INFO] [stderr]      Running /opt/crater/target/debug/deps/tail-4d46520105ad0cde
[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] [stderr]    Doc-tests tail
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test src/lib.rs - BackwardsReader (line 23) ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- src/lib.rs - BackwardsReader (line 23) stdout ----
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared type or module `BufWriter`
[INFO] [stdout]  --> src/lib.rs:24:18
[INFO] [stdout]   |
[INFO] [stdout] 3 | let mut writer = BufWriter::new(std::io::stdout());
[INFO] [stdout]   |                  ^^^^^^^^^ use of undeclared type or module `BufWriter`
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared type or module `BackwardsReader`
[INFO] [stdout]  --> src/lib.rs:25:18
[INFO] [stdout]   |
[INFO] [stdout] 4 | let mut reader = BackwardsReader::new(10, &mut writer);
[INFO] [stdout]   |                  ^^^^^^^^^^^^^^^ use of undeclared type or module `BackwardsReader`
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0433`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     src/lib.rs - BackwardsReader (line 23)
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr] error: test failed, to rerun pass '--doc'
[INFO] running `"docker" "inspect" "83df0ccf11a3057621c0a9e71d91c18065492c2708985f2b93f98d1c81698653"`
[INFO] running `"docker" "rm" "-f" "83df0ccf11a3057621c0a9e71d91c18065492c2708985f2b93f98d1c81698653"`
[INFO] [stdout] 83df0ccf11a3057621c0a9e71d91c18065492c2708985f2b93f98d1c81698653