[INFO] fetching crate multitooth 0.0.1...
[INFO] checking multitooth-0.0.1 against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] extracting crate multitooth 0.0.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate multitooth 0.0.1 on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate multitooth 0.0.1
[INFO] finished tweaking crates.io crate multitooth 0.0.1
[INFO] tweaked toml for crates.io crate multitooth 0.0.1 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a6698db0a9e6b809b71a324e4ad7c34c316e275f2062ad2c6962ff99b61147c3
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "a6698db0a9e6b809b71a324e4ad7c34c316e275f2062ad2c6962ff99b61147c3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a6698db0a9e6b809b71a324e4ad7c34c316e275f2062ad2c6962ff99b61147c3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a6698db0a9e6b809b71a324e4ad7c34c316e275f2062ad2c6962ff99b61147c3", kill_on_drop: false }`
[INFO] [stdout] a6698db0a9e6b809b71a324e4ad7c34c316e275f2062ad2c6962ff99b61147c3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f1e4366e9ba383b19d44ed4e5bc2d1dea2938415ef80b90bc75067f17ca9eecf
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "f1e4366e9ba383b19d44ed4e5bc2d1dea2938415ef80b90bc75067f17ca9eecf", kill_on_drop: false }`
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking getopts v0.2.21
[INFO] [stderr]     Checking multitooth v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::os`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::os;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ErrorKind`, `Error`
[INFO] [stdout]   --> src/main.rs:11:15
[INFO] [stdout]    |
[INFO] [stdout] 11 | use std::io::{Error,ErrorKind};
[INFO] [stdout]    |               ^^^^^ ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::os`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::os;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ErrorKind`, `Error`
[INFO] [stdout]   --> src/main.rs:11:15
[INFO] [stdout]    |
[INFO] [stdout] 11 | use std::io::{Error,ErrorKind};
[INFO] [stdout]    |               ^^^^^ ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/main.rs:48:25
[INFO] [stdout]    |
[INFO] [stdout] 45 |                             panic!(e);
[INFO] [stdout]    |                             ---------- any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 48 |                         unsafe { ::std::mem::forget(stdout) };
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `tail` found for struct `std::vec::Vec<std::string::String>` in the current scope
[INFO] [stdout]   --> src/main.rs:99:41
[INFO] [stdout]    |
[INFO] [stdout] 99 |     let matches = match opts.parse(args.tail()) {
[INFO] [stdout]    |                                         ^^^^ method not found in `std::vec::Vec<std::string::String>`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/main.rs:48:25
[INFO] [stdout]    |
[INFO] [stdout] 45 |                             panic!(e);
[INFO] [stdout]    |                             ---------- any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 48 |                         unsafe { ::std::mem::forget(stdout) };
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `multitooth`.
[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] [stdout] error[E0599]: no method named `tail` found for struct `std::vec::Vec<std::string::String>` in the current scope
[INFO] [stdout]   --> src/main.rs:99:41
[INFO] [stdout]    |
[INFO] [stdout] 99 |     let matches = match opts.parse(args.tail()) {
[INFO] [stdout]    |                                         ^^^^ method not found in `std::vec::Vec<std::string::String>`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "f1e4366e9ba383b19d44ed4e5bc2d1dea2938415ef80b90bc75067f17ca9eecf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1e4366e9ba383b19d44ed4e5bc2d1dea2938415ef80b90bc75067f17ca9eecf", kill_on_drop: false }`
[INFO] [stdout] f1e4366e9ba383b19d44ed4e5bc2d1dea2938415ef80b90bc75067f17ca9eecf