Dec 19 04:57:55.268 INFO checking yoshuawuyts/exponential-backoff against try#e70472fc501b855c9080f3772432c10fe20b8866 for pr-56955
Dec 19 04:57:55.272 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56955/worker-4/try#e70472fc501b855c9080f3772432c10fe20b8866:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-56955/sources/try#e70472fc501b855c9080f3772432c10fe20b8866/gh/yoshuawuyts/exponential-backoff:/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" "+e70472fc501b855c9080f3772432c10fe20b8866-alt" "check" "--frozen" "--all" "--all-targets"`
Dec 19 04:57:55.668 INFO [stdout] b0cbb2bcc948e20e0a47488c137f64f43214f4a23f3bf1d4a312be3b5a72d646
Dec 19 04:57:55.668 INFO running `"docker" "start" "-a" "b0cbb2bcc948e20e0a47488c137f64f43214f4a23f3bf1d4a312be3b5a72d646"`
Dec 19 04:57:57.396 INFO [stderr]     Checking rand_core v0.2.1
Dec 19 04:57:57.892 INFO [stderr]     Checking rand v0.5.3
Dec 19 04:58:00.109 INFO [stderr]     Checking exponential-backoff v0.2.3-alpha.0 (/opt/crater/workdir)
Dec 19 04:58:00.819 INFO [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.50s
Dec 19 04:58:01.876 INFO running `"docker" "inspect" "b0cbb2bcc948e20e0a47488c137f64f43214f4a23f3bf1d4a312be3b5a72d646"`
Dec 19 04:58:02.122 INFO running `"docker" "rm" "-f" "b0cbb2bcc948e20e0a47488c137f64f43214f4a23f3bf1d4a312be3b5a72d646"`
Dec 19 04:58:02.459 INFO [stdout] b0cbb2bcc948e20e0a47488c137f64f43214f4a23f3bf1d4a312be3b5a72d646