[INFO] updating cached repository neosmart/tac
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/neosmart/tac
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/neosmart/tac" "work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/neosmart/tac"`
[INFO] [stderr] Cloning into 'work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/neosmart/tac'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/neosmart/tac" "work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/neosmart/tac"`
[INFO] [stderr] Cloning into 'work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/neosmart/tac'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 0a8ff09e84e9d9eccbf164b914f17f39e397a312
[INFO] sha for GitHub repo neosmart/tac: 0a8ff09e84e9d9eccbf164b914f17f39e397a312
[INFO] validating manifest of neosmart/tac on toolchain master#5f9c0448dde167128d668da4555879f64e56af1d
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of neosmart/tac on toolchain try#8ec8125bea94852768b56958f05da47666c21ab0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+8ec8125bea94852768b56958f05da47666c21ab0-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing neosmart/tac
[INFO] finished frobbing neosmart/tac
[INFO] frobbed toml for neosmart/tac written to work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/neosmart/tac/Cargo.toml
[INFO] started frobbing neosmart/tac
[INFO] finished frobbing neosmart/tac
[INFO] frobbed toml for neosmart/tac written to work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/neosmart/tac/Cargo.toml
[INFO] crate neosmart/tac already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+8ec8125bea94852768b56958f05da47666c21ab0-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] checking neosmart/tac against master#5f9c0448dde167128d668da4555879f64e56af1d for pr-62133
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-62133/worker-0/master#5f9c0448dde167128d668da4555879f64e56af1d:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/neosmart/tac:/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" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 08528c9296afc2cfec2cf325215c97682a9f5fafa7693a70ae9644da4d2d99a2
[INFO] running `"docker" "start" "-a" "08528c9296afc2cfec2cf325215c97682a9f5fafa7693a70ae9644da4d2d99a2"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking memmap v0.5.2
[INFO] [stderr]     Checking tac v0.2.3 (/opt/crater/workdir)
[INFO] [stderr] warning: the item `Write` is imported redundantly
[INFO] [stderr]   --> src/main.rs:72:9
[INFO] [stderr]    |
[INFO] [stderr] 5  | use std::io::{Stdout, Write};
[INFO] [stderr]    |                       ----- the item `Write` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 72 |     use std::io::Write;
[INFO] [stderr]    |         ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: the item `Write` is imported redundantly
[INFO] [stderr]   --> src/main.rs:72:9
[INFO] [stderr]    |
[INFO] [stderr] 5  | use std::io::{Stdout, Write};
[INFO] [stderr]    |                       ----- the item `Write` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 72 |     use std::io::Write;
[INFO] [stderr]    |         ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:64:16
[INFO] [stderr]    |
[INFO] [stderr] 64 | fn print_bytes(mut stdout: &mut Stdout, bytes: &[u8]) {
[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:64:16
[INFO] [stderr]    |
[INFO] [stderr] 64 | fn print_bytes(mut stdout: &mut Stdout, bytes: &[u8]) {
[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]     Finished dev [unoptimized + debuginfo] target(s) in 1.59s
[INFO] running `"docker" "inspect" "08528c9296afc2cfec2cf325215c97682a9f5fafa7693a70ae9644da4d2d99a2"`
[INFO] running `"docker" "rm" "-f" "08528c9296afc2cfec2cf325215c97682a9f5fafa7693a70ae9644da4d2d99a2"`
[INFO] [stdout] 08528c9296afc2cfec2cf325215c97682a9f5fafa7693a70ae9644da4d2d99a2