[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/pr-63565/sources/master#c43d03a19f326f4a323569328cc501e86eb6d22e/gh/RobotDisco/rust_chat"`
[INFO] [stderr] Cloning into 'work/ex/pr-63565/sources/master#c43d03a19f326f4a323569328cc501e86eb6d22e/gh/RobotDisco/rust_chat'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/RobotDisco/rust_chat" "work/ex/pr-63565/sources/try#75eff020d0923c035c2fe220db4a0465cd847048/gh/RobotDisco/rust_chat"`
[INFO] [stderr] Cloning into 'work/ex/pr-63565/sources/try#75eff020d0923c035c2fe220db4a0465cd847048/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 master#c43d03a19f326f4a323569328cc501e86eb6d22e
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c43d03a19f326f4a323569328cc501e86eb6d22e-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of RobotDisco/rust_chat on toolchain try#75eff020d0923c035c2fe220db4a0465cd847048
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+75eff020d0923c035c2fe220db4a0465cd847048-alt" "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/pr-63565/sources/master#c43d03a19f326f4a323569328cc501e86eb6d22e/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/pr-63565/sources/try#75eff020d0923c035c2fe220db4a0465cd847048/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" "+c43d03a19f326f4a323569328cc501e86eb6d22e-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" "+75eff020d0923c035c2fe220db4a0465cd847048-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking RobotDisco/rust_chat against try#75eff020d0923c035c2fe220db4a0465cd847048 for pr-63565
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-63565/worker-4/try#75eff020d0923c035c2fe220db4a0465cd847048:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-63565/sources/try#75eff020d0923c035c2fe220db4a0465cd847048/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=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" "+75eff020d0923c035c2fe220db4a0465cd847048-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] ac892bf5f5fdd25b1def8c5ec741ccd2c17dab7610dc70c447ae41735a1ca41c
[INFO] running `"docker" "start" "-a" "ac892bf5f5fdd25b1def8c5ec741ccd2c17dab7610dc70c447ae41735a1ca41c"`
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking nix v0.5.1
[INFO] [stderr]     Checking sha1 v0.1.1
[INFO] [stderr]     Checking http-muncher v0.2.5
[INFO] [stderr]     Checking miow v0.1.5
[INFO] [stderr]     Checking mio v0.5.1
[INFO] [stderr]     Checking 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] 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 6.60s
[INFO] running `"docker" "inspect" "ac892bf5f5fdd25b1def8c5ec741ccd2c17dab7610dc70c447ae41735a1ca41c"`
[INFO] running `"docker" "rm" "-f" "ac892bf5f5fdd25b1def8c5ec741ccd2c17dab7610dc70c447ae41735a1ca41c"`
[INFO] [stdout] ac892bf5f5fdd25b1def8c5ec741ccd2c17dab7610dc70c447ae41735a1ca41c