[INFO] crate maybe-single 0.7.0 is already in cache
[INFO] checking maybe-single-0.7.0 against master#73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de for pr-68325
[INFO] extracting crate maybe-single 0.7.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate maybe-single 0.7.0 on toolchain 73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de
[INFO] running `"/workspace/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate maybe-single 0.7.0
[INFO] finished tweaking crates.io crate maybe-single 0.7.0
[INFO] tweaked toml for crates.io crate maybe-single 0.7.0 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 704a856af2b0f6c44a4aa343c36e5b2da3684dade7369492490b1dee9adbace9
[INFO] running `"docker" "start" "-a" "704a856af2b0f6c44a4aa343c36e5b2da3684dade7369492490b1dee9adbace9"`
[INFO] [stderr]     Checking maybe-single v0.7.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: field is never read: `read_lock`
[INFO] [stderr]   --> src/lib.rs:91:5
[INFO] [stderr]    |
[INFO] [stderr] 91 |     read_lock: Option<RwLockReadGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `write_lock`
[INFO] [stderr]   --> src/lib.rs:92:5
[INFO] [stderr]    |
[INFO] [stderr] 92 |     write_lock: Option<RwLockWriteGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `read_lock`
[INFO] [stderr]   --> src/lib.rs:91:5
[INFO] [stderr]    |
[INFO] [stderr] 91 |     read_lock: Option<RwLockReadGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `write_lock`
[INFO] [stderr]   --> src/lib.rs:92:5
[INFO] [stderr]    |
[INFO] [stderr] 92 |     write_lock: Option<RwLockWriteGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.35s
[INFO] running `"docker" "inspect" "704a856af2b0f6c44a4aa343c36e5b2da3684dade7369492490b1dee9adbace9"`
[INFO] running `"docker" "rm" "-f" "704a856af2b0f6c44a4aa343c36e5b2da3684dade7369492490b1dee9adbace9"`
[INFO] [stdout] 704a856af2b0f6c44a4aa343c36e5b2da3684dade7369492490b1dee9adbace9