[INFO] fetching crate cow 0.0.8...
[INFO] checking cow-0.0.8 against master#31ee872db5aae4750e3da1ca4ed1523c4356947f for pr-78461
[INFO] extracting crate cow 0.0.8 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate cow 0.0.8 on toolchain 31ee872db5aae4750e3da1ca4ed1523c4356947f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cow 0.0.8
[INFO] finished tweaking crates.io crate cow 0.0.8
[INFO] tweaked toml for crates.io crate cow 0.0.8 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: path `/workspace/builds/worker-2/source/src/cow.rs` was erroneously implicitly accepted for library `cow`,
[INFO] [stderr] please rename the file to `src/lib.rs` or set lib.path in Cargo.toml
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 97d53a2adbc8cc13bf867c1be7307517fb5cc3e7fc582c960f57b4e038b5bade
[INFO] running `Command { std: "docker" "start" "-a" "97d53a2adbc8cc13bf867c1be7307517fb5cc3e7fc582c960f57b4e038b5bade", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "97d53a2adbc8cc13bf867c1be7307517fb5cc3e7fc582c960f57b4e038b5bade", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "97d53a2adbc8cc13bf867c1be7307517fb5cc3e7fc582c960f57b4e038b5bade", kill_on_drop: false }`
[INFO] [stdout] 97d53a2adbc8cc13bf867c1be7307517fb5cc3e7fc582c960f57b4e038b5bade
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 0b27fe3f2b1b46622f2acfe28144a26f6dc76ed5205cbc43b3fa0aaa29a329ec
[INFO] running `Command { std: "docker" "start" "-a" "0b27fe3f2b1b46622f2acfe28144a26f6dc76ed5205cbc43b3fa0aaa29a329ec", kill_on_drop: false }`
[INFO] [stderr] warning: path `/opt/rustwide/workdir/src/cow.rs` was erroneously implicitly accepted for library `cow`,
[INFO] [stderr] please rename the file to `src/lib.rs` or set lib.path in Cargo.toml
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]     Checking cow v0.0.8 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0463]: can't find crate for `collections`
[INFO] [stdout]  --> src/cow.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | extern crate collections;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0463]: can't find crate for `collections`
[INFO] [stdout]  --> src/cow.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | extern crate collections;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `cow`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "0b27fe3f2b1b46622f2acfe28144a26f6dc76ed5205cbc43b3fa0aaa29a329ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0b27fe3f2b1b46622f2acfe28144a26f6dc76ed5205cbc43b3fa0aaa29a329ec", kill_on_drop: false }`
[INFO] [stdout] 0b27fe3f2b1b46622f2acfe28144a26f6dc76ed5205cbc43b3fa0aaa29a329ec