[INFO] crate rustsync 0.2.3 is already in cache
[INFO] extracting crate rustsync 0.2.3 into work/ex/beta-1.37-6/sources/1.36.0/reg/rustsync/0.2.3
[INFO] extracting crate rustsync 0.2.3 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/rustsync/0.2.3
[INFO] validating manifest of rustsync-0.2.3 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 rustsync-0.2.3 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 rustsync-0.2.3
[INFO] finished frobbing rustsync-0.2.3
[INFO] frobbed toml for rustsync-0.2.3 written to work/ex/beta-1.37-6/sources/1.36.0/reg/rustsync/0.2.3/Cargo.toml
[INFO] started frobbing rustsync-0.2.3
[INFO] finished frobbing rustsync-0.2.3
[INFO] frobbed toml for rustsync-0.2.3 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/rustsync/0.2.3/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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 rustsync-0.2.3 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-1/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/rustsync/0.2.3:/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] 7f98d5848b43f9c65579eb03ec56eb0e8be8feaf5f2f0c4b2669f2a4e8d5feac
[INFO] running `"docker" "start" "-a" "7f98d5848b43f9c65579eb03ec56eb0e8be8feaf5f2f0c4b2669f2a4e8d5feac"`
[INFO] [stderr]    Compiling blake2-rfc v0.2.18
[INFO] [stderr]    Compiling rustsync v0.2.3 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/lib.rs:243:41
[INFO] [stderr]     |
[INFO] [stderr] 243 |                 if let Async::Ready((r, mut block, len)) = reading.poll()? {
[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/lib.rs:430:29
[INFO] [stderr]     |
[INFO] [stderr] 430 |                         let mut hash = adler32::RollingAdler32::from_buffer(&block.as_ref()[..len]);
[INFO] [stderr]     |                             ----^^^^
[INFO] [stderr]     |                             |
[INFO] [stderr]     |                             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.50s
[INFO] running `"docker" "inspect" "7f98d5848b43f9c65579eb03ec56eb0e8be8feaf5f2f0c4b2669f2a4e8d5feac"`
[INFO] running `"docker" "rm" "-f" "7f98d5848b43f9c65579eb03ec56eb0e8be8feaf5f2f0c4b2669f2a4e8d5feac"`
[INFO] [stdout] 7f98d5848b43f9c65579eb03ec56eb0e8be8feaf5f2f0c4b2669f2a4e8d5feac
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-1/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/rustsync/0.2.3:/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] a5babafd554a2e6d6f956010b28bf9f4227a86c2d2b4441c57226f2ad881a620
[INFO] running `"docker" "start" "-a" "a5babafd554a2e6d6f956010b28bf9f4227a86c2d2b4441c57226f2ad881a620"`
[INFO] [stderr]    Compiling rustsync v0.2.3 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/lib.rs:243:41
[INFO] [stderr]     |
[INFO] [stderr] 243 |                 if let Async::Ready((r, mut block, len)) = reading.poll()? {
[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/lib.rs:430:29
[INFO] [stderr]     |
[INFO] [stderr] 430 |                         let mut hash = adler32::RollingAdler32::from_buffer(&block.as_ref()[..len]);
[INFO] [stderr]     |                             ----^^^^
[INFO] [stderr]     |                             |
[INFO] [stderr]     |                             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.04s
[INFO] running `"docker" "inspect" "a5babafd554a2e6d6f956010b28bf9f4227a86c2d2b4441c57226f2ad881a620"`
[INFO] running `"docker" "rm" "-f" "a5babafd554a2e6d6f956010b28bf9f4227a86c2d2b4441c57226f2ad881a620"`
[INFO] [stdout] a5babafd554a2e6d6f956010b28bf9f4227a86c2d2b4441c57226f2ad881a620
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-1/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/rustsync/0.2.3:/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] 65da0f140546bb957787d0649f855294e7a68e8b5fbb0ed563d3e7b6a8d3df8e
[INFO] running `"docker" "start" "-a" "65da0f140546bb957787d0649f855294e7a68e8b5fbb0ed563d3e7b6a8d3df8e"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.07s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/rustsync-a475ea315a4cd6ce
[INFO] [stdout] 
[INFO] [stdout] running 2 tests
[INFO] [stdout] test tests::futures ... ok
[INFO] [stdout] test tests::basic ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests rustsync
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test src/lib.rs -  (line 4) ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "65da0f140546bb957787d0649f855294e7a68e8b5fbb0ed563d3e7b6a8d3df8e"`
[INFO] running `"docker" "rm" "-f" "65da0f140546bb957787d0649f855294e7a68e8b5fbb0ed563d3e7b6a8d3df8e"`
[INFO] [stdout] 65da0f140546bb957787d0649f855294e7a68e8b5fbb0ed563d3e7b6a8d3df8e