[INFO] cloning repository https://github.com/jonny7/rust-references
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jonny7/rust-references" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjonny7%2Frust-references", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjonny7%2Frust-references'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 72a87e2425a865dafd9c7cdb507a3fd063ecd07f
[INFO] checking jonny7/rust-references against try#f6e2f78768c57172b99c3e85892f867894dc7e30 for pr-75502
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjonny7%2Frust-references" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jonny7/rust-references on toolchain f6e2f78768c57172b99c3e85892f867894dc7e30
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jonny7/rust-references
[INFO] finished tweaking git repo https://github.com/jonny7/rust-references
[INFO] tweaked toml for git repo https://github.com/jonny7/rust-references written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/jonny7/rust-references already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "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" "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:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fcda9d07500ea117f834b1d00c843cde243d2eef131c98d91c25252c1940e9b9
[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" "fcda9d07500ea117f834b1d00c843cde243d2eef131c98d91c25252c1940e9b9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fcda9d07500ea117f834b1d00c843cde243d2eef131c98d91c25252c1940e9b9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fcda9d07500ea117f834b1d00c843cde243d2eef131c98d91c25252c1940e9b9", kill_on_drop: false }`
[INFO] [stdout] fcda9d07500ea117f834b1d00c843cde243d2eef131c98d91c25252c1940e9b9
[INFO] running `Command { std: "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" "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:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a7fc7e14a85eab66b7fa23b3393b36d1c69eb5f4421d32c8b80d03e07172f357
[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" "a7fc7e14a85eab66b7fa23b3393b36d1c69eb5f4421d32c8b80d03e07172f357", kill_on_drop: false }`
[INFO] [stderr]     Checking references v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/main.rs:23:13
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let r1 = &mut t;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/main.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let r2 = &mut t;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/main.rs:23:13
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let r1 = &mut t;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/main.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let r2 = &mut t;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.22s
[INFO] running `Command { std: "docker" "inspect" "a7fc7e14a85eab66b7fa23b3393b36d1c69eb5f4421d32c8b80d03e07172f357", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a7fc7e14a85eab66b7fa23b3393b36d1c69eb5f4421d32c8b80d03e07172f357", kill_on_drop: false }`
[INFO] [stdout] a7fc7e14a85eab66b7fa23b3393b36d1c69eb5f4421d32c8b80d03e07172f357