[INFO] updating cached repository RobotDisco/rust_chat
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/RobotDisco/rust_chat
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/RobotDisco/rust_chat" "work/ex/beta-1.37-6/sources/1.36.0/gh/RobotDisco/rust_chat"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/RobotDisco/rust_chat'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/RobotDisco/rust_chat" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/RobotDisco/rust_chat"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/RobotDisco/rust_chat'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b039b619dc4f0f297228d09a894a0c41808447a9
[INFO] sha for GitHub repo RobotDisco/rust_chat: b039b619dc4f0f297228d09a894a0c41808447a9
[INFO] validating manifest of RobotDisco/rust_chat 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 RobotDisco/rust_chat 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 RobotDisco/rust_chat
[INFO] finished frobbing RobotDisco/rust_chat
[INFO] frobbed toml for RobotDisco/rust_chat written to work/ex/beta-1.37-6/sources/1.36.0/gh/RobotDisco/rust_chat/Cargo.toml
[INFO] started frobbing RobotDisco/rust_chat
[INFO] finished frobbing RobotDisco/rust_chat
[INFO] frobbed toml for RobotDisco/rust_chat written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/RobotDisco/rust_chat/Cargo.toml
[INFO] crate RobotDisco/rust_chat already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache lock
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing RobotDisco/rust_chat against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-3/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/RobotDisco/rust_chat:/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-2019-07-23" "build" "--frozen"`
[INFO] [stdout] 78a7e0b0c6a097c0748630766ba836a7235ced420f98da7d85ddb36feaea3d08
[INFO] running `"docker" "start" "-a" "78a7e0b0c6a097c0748630766ba836a7235ced420f98da7d85ddb36feaea3d08"`
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling http-muncher v0.2.5
[INFO] [stderr]    Compiling nix v0.5.1
[INFO] [stderr]    Compiling sha1 v0.1.1
[INFO] [stderr]    Compiling miow v0.1.5
[INFO] [stderr]    Compiling mio v0.5.1
[INFO] [stderr]    Compiling chat v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:192:25
[INFO] [stderr]     |
[INFO] [stderr] 192 |                     let mut client = self.clients.get_mut(&token).unwrap();
[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 10.54s
[INFO] running `"docker" "inspect" "78a7e0b0c6a097c0748630766ba836a7235ced420f98da7d85ddb36feaea3d08"`
[INFO] running `"docker" "rm" "-f" "78a7e0b0c6a097c0748630766ba836a7235ced420f98da7d85ddb36feaea3d08"`
[INFO] [stdout] 78a7e0b0c6a097c0748630766ba836a7235ced420f98da7d85ddb36feaea3d08
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-3/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/RobotDisco/rust_chat:/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-2019-07-23" "test" "--frozen" "--no-run"`
[INFO] [stdout] d5c84d941f74cec895b75a79a1dc252caffd5fbb1e9d352c89221001c30cda0d
[INFO] running `"docker" "start" "-a" "d5c84d941f74cec895b75a79a1dc252caffd5fbb1e9d352c89221001c30cda0d"`
[INFO] [stderr]    Compiling chat v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:192:25
[INFO] [stderr]     |
[INFO] [stderr] 192 |                     let mut client = self.clients.get_mut(&token).unwrap();
[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 0.91s
[INFO] running `"docker" "inspect" "d5c84d941f74cec895b75a79a1dc252caffd5fbb1e9d352c89221001c30cda0d"`
[INFO] running `"docker" "rm" "-f" "d5c84d941f74cec895b75a79a1dc252caffd5fbb1e9d352c89221001c30cda0d"`
[INFO] [stdout] d5c84d941f74cec895b75a79a1dc252caffd5fbb1e9d352c89221001c30cda0d
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-3/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/RobotDisco/rust_chat:/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-2019-07-23" "test" "--frozen"`
[INFO] [stdout] 8d23015ffab09fc699a61b384dd2cce1f55b035922ac1221feb4bfdb6f0a4ce2
[INFO] running `"docker" "start" "-a" "8d23015ffab09fc699a61b384dd2cce1f55b035922ac1221feb4bfdb6f0a4ce2"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.04s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/chat-bebb256cbf2c992a
[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] running `"docker" "inspect" "8d23015ffab09fc699a61b384dd2cce1f55b035922ac1221feb4bfdb6f0a4ce2"`
[INFO] running `"docker" "rm" "-f" "8d23015ffab09fc699a61b384dd2cce1f55b035922ac1221feb4bfdb6f0a4ce2"`
[INFO] [stdout] 8d23015ffab09fc699a61b384dd2cce1f55b035922ac1221feb4bfdb6f0a4ce2