[INFO] fetching crate serde_tuple 0.4.0...
[INFO] checking serde_tuple-0.4.0 against try#e60d9e09c55855f5a848fde8ad83e13131a5b241 for pr-68350
[INFO] extracting crate serde_tuple 0.4.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate serde_tuple 0.4.0 on toolchain e60d9e09c55855f5a848fde8ad83e13131a5b241
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e60d9e09c55855f5a848fde8ad83e13131a5b241" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate serde_tuple 0.4.0
[INFO] finished tweaking crates.io crate serde_tuple 0.4.0
[INFO] tweaked toml for crates.io crate serde_tuple 0.4.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate serde_tuple 0.4.0 already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e60d9e09c55855f5a848fde8ad83e13131a5b241" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+e60d9e09c55855f5a848fde8ad83e13131a5b241" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 193c4146a6d26fab2220409142b749452ef412ecd44c0a93f214b618bd6b9c21
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "193c4146a6d26fab2220409142b749452ef412ecd44c0a93f214b618bd6b9c21"`
[INFO] [stderr]    Compiling syn v0.15.36
[INFO] [stderr]     Checking proc-macro2 v1.0.7
[INFO] [stderr]     Checking quote v1.0.2
[INFO] [stderr]     Checking syn v1.0.13
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]     Checking serde v1.0.92
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking serde_tuple v0.4.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `std::borrow::Cow`
[INFO] [stderr]  --> examples/simple.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::borrow::Cow;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Ok`
[INFO] [stderr]   --> examples/simple.rs:20:8
[INFO] [stderr]    |
[INFO] [stderr] 20 | struct Ok;
[INFO] [stderr]    |        ^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 55.88s
[INFO] running `"docker" "inspect" "193c4146a6d26fab2220409142b749452ef412ecd44c0a93f214b618bd6b9c21"`
[INFO] running `"docker" "rm" "-f" "193c4146a6d26fab2220409142b749452ef412ecd44c0a93f214b618bd6b9c21"`
[INFO] [stdout] 193c4146a6d26fab2220409142b749452ef412ecd44c0a93f214b618bd6b9c21