Dec 19 15:11:27.546 INFO checking jimblandy/chat-mio against master#d99a320cba42f661aebfa1293b7b2ec3603dda75 for pr-56955
Dec 19 15:11:27.546 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56955/worker-6/master#d99a320cba42f661aebfa1293b7b2ec3603dda75:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-56955/sources/master#d99a320cba42f661aebfa1293b7b2ec3603dda75/gh/jimblandy/chat-mio:/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" "+d99a320cba42f661aebfa1293b7b2ec3603dda75-alt" "check" "--frozen" "--all" "--all-targets"`
Dec 19 15:11:28.091 INFO [stdout] 84a8fdcfe76f93a711d80c04449f1bda284828ff9637e988a5a8d61f7c3bcca1
Dec 19 15:11:28.094 INFO running `"docker" "start" "-a" "84a8fdcfe76f93a711d80c04449f1bda284828ff9637e988a5a8d61f7c3bcca1"`
Dec 19 15:11:30.845 INFO [stderr]     Checking net2 v0.2.26
Dec 19 15:11:30.861 INFO [stderr]     Checking nix v0.7.0
Dec 19 15:11:34.336 INFO [stderr]     Checking mio v0.6.1
Dec 19 15:11:35.382 INFO [stderr]     Checking chat-mio v0.1.0 (/opt/crater/workdir)
Dec 19 15:11:35.944 INFO [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.21s
Dec 19 15:11:36.494 INFO running `"docker" "inspect" "84a8fdcfe76f93a711d80c04449f1bda284828ff9637e988a5a8d61f7c3bcca1"`
Dec 19 15:11:36.930 INFO running `"docker" "rm" "-f" "84a8fdcfe76f93a711d80c04449f1bda284828ff9637e988a5a8d61f7c3bcca1"`
Dec 19 15:11:37.316 INFO [stdout] 84a8fdcfe76f93a711d80c04449f1bda284828ff9637e988a5a8d61f7c3bcca1