Dec 19 18:45:33.926 INFO checking cowang4/rusty_tree against master#d99a320cba42f661aebfa1293b7b2ec3603dda75 for pr-56955
Dec 19 18:45:33.926 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56955/worker-4/master#d99a320cba42f661aebfa1293b7b2ec3603dda75:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-56955/sources/master#d99a320cba42f661aebfa1293b7b2ec3603dda75/gh/cowang4/rusty_tree:/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 18:45:34.371 INFO [stdout] 664fbd6560819a24b0cae5776b3a44c7dbc919de5708586bf7cb05cf5a6299b5
Dec 19 18:45:34.371 INFO running `"docker" "start" "-a" "664fbd6560819a24b0cae5776b3a44c7dbc919de5708586bf7cb05cf5a6299b5"`
Dec 19 18:45:35.936 INFO [stderr]    Compiling serde v1.0.57
Dec 19 18:45:35.938 INFO [stderr]    Compiling serde_derive v1.0.57
Dec 19 18:45:55.607 INFO [stderr]     Checking docopt v1.0.0
Dec 19 18:45:57.144 INFO [stderr]     Checking rusty_tree v0.1.0 (/opt/crater/workdir)
Dec 19 18:45:58.382 INFO [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 22.57s
Dec 19 18:45:59.283 INFO running `"docker" "inspect" "664fbd6560819a24b0cae5776b3a44c7dbc919de5708586bf7cb05cf5a6299b5"`
Dec 19 18:45:59.528 INFO running `"docker" "rm" "-f" "664fbd6560819a24b0cae5776b3a44c7dbc919de5708586bf7cb05cf5a6299b5"`
Dec 19 18:45:59.916 INFO [stdout] 664fbd6560819a24b0cae5776b3a44c7dbc919de5708586bf7cb05cf5a6299b5