[INFO] crate color_quant 1.0.1 is already in cache
[INFO] extracting crate color_quant 1.0.1 into work/ex/beta-1.37-6/sources/1.36.0/reg/color_quant/1.0.1
[INFO] extracting crate color_quant 1.0.1 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/color_quant/1.0.1
[INFO] validating manifest of color_quant-1.0.1 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 color_quant-1.0.1 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 color_quant-1.0.1
[INFO] finished frobbing color_quant-1.0.1
[INFO] frobbed toml for color_quant-1.0.1 written to work/ex/beta-1.37-6/sources/1.36.0/reg/color_quant/1.0.1/Cargo.toml
[INFO] started frobbing color_quant-1.0.1
[INFO] finished frobbing color_quant-1.0.1
[INFO] frobbed toml for color_quant-1.0.1 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/color_quant/1.0.1/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] [stderr]     Blocking waiting for file lock on package cache
[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 color_quant-1.0.1 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-7/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/color_quant/1.0.1:/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] cd1dc22fe3420615c897e3f42d210ff11fe7c8a4a6b7cb0c3caba72e6a7e5896
[INFO] running `"docker" "start" "-a" "cd1dc22fe3420615c897e3f42d210ff11fe7c8a4a6b7cb0c3caba72e6a7e5896"`
[INFO] [stderr]    Compiling color_quant v1.0.1 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/lib.rs:368:21
[INFO] [stderr]     |
[INFO] [stderr] 368 |                 let mut j;
[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 0.82s
[INFO] running `"docker" "inspect" "cd1dc22fe3420615c897e3f42d210ff11fe7c8a4a6b7cb0c3caba72e6a7e5896"`
[INFO] running `"docker" "rm" "-f" "cd1dc22fe3420615c897e3f42d210ff11fe7c8a4a6b7cb0c3caba72e6a7e5896"`
[INFO] [stdout] cd1dc22fe3420615c897e3f42d210ff11fe7c8a4a6b7cb0c3caba72e6a7e5896
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-7/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/color_quant/1.0.1:/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] fd27963947e789533c7f3a431dc9d5c1edc16e6d891f9b3a66988bbc4249d1e0
[INFO] running `"docker" "start" "-a" "fd27963947e789533c7f3a431dc9d5c1edc16e6d891f9b3a66988bbc4249d1e0"`
[INFO] [stderr]    Compiling color_quant v1.0.1 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/lib.rs:368:21
[INFO] [stderr]     |
[INFO] [stderr] 368 |                 let mut j;
[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 0.67s
[INFO] running `"docker" "inspect" "fd27963947e789533c7f3a431dc9d5c1edc16e6d891f9b3a66988bbc4249d1e0"`
[INFO] running `"docker" "rm" "-f" "fd27963947e789533c7f3a431dc9d5c1edc16e6d891f9b3a66988bbc4249d1e0"`
[INFO] [stdout] fd27963947e789533c7f3a431dc9d5c1edc16e6d891f9b3a66988bbc4249d1e0
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-7/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/color_quant/1.0.1:/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] 78f16d18ca78efbf7df114d596dc1c292624af9348f1927e89e0aaeab145f2bd
[INFO] running `"docker" "start" "-a" "78f16d18ca78efbf7df114d596dc1c292624af9348f1927e89e0aaeab145f2bd"`
[INFO] [stderr]     Blocking waiting for file lock on package cache lock
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/color_quant-21311c01e326727f
[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 color_quant
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test src/lib.rs -  (line 56) ... 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" "78f16d18ca78efbf7df114d596dc1c292624af9348f1927e89e0aaeab145f2bd"`
[INFO] running `"docker" "rm" "-f" "78f16d18ca78efbf7df114d596dc1c292624af9348f1927e89e0aaeab145f2bd"`
[INFO] [stdout] 78f16d18ca78efbf7df114d596dc1c292624af9348f1927e89e0aaeab145f2bd