[INFO] cloning repository https://github.com/benlubas/how-does-rust-work
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/benlubas/how-does-rust-work" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenlubas%2Fhow-does-rust-work", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenlubas%2Fhow-does-rust-work'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 620107f627a3494aaaf4005d5ad7f1e110ac2047
[INFO] checking benlubas/how-does-rust-work against try#353a0a223066e9f46a1d935f2271a26c3c5002bb for pr-75180
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenlubas%2Fhow-does-rust-work" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/benlubas/how-does-rust-work on toolchain 353a0a223066e9f46a1d935f2271a26c3c5002bb
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/benlubas/how-does-rust-work
[INFO] finished tweaking git repo https://github.com/benlubas/how-does-rust-work
[INFO] tweaked toml for git repo https://github.com/benlubas/how-does-rust-work written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/benlubas/how-does-rust-work already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "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] dd7e0fd03f21ce02e34d052795c902c64adf730122b193711275ce35e2c6020b
[INFO] running `Command { std: "docker" "start" "-a" "dd7e0fd03f21ce02e34d052795c902c64adf730122b193711275ce35e2c6020b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dd7e0fd03f21ce02e34d052795c902c64adf730122b193711275ce35e2c6020b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dd7e0fd03f21ce02e34d052795c902c64adf730122b193711275ce35e2c6020b", kill_on_drop: false }`
[INFO] [stdout] dd7e0fd03f21ce02e34d052795c902c64adf730122b193711275ce35e2c6020b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5ab63bd7ab8c9fe5679ce533f1d4f7afd1314b64770124d24070099747bc76bd
[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" "5ab63bd7ab8c9fe5679ce533f1d4f7afd1314b64770124d24070099747bc76bd", kill_on_drop: false }`
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stderr]     Checking how-does-rust-work v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `maybe_none`
[INFO] [stdout]   --> src/day7_match.rs:39:7
[INFO] [stdout]    |
[INFO] [stdout] 39 |   let maybe_none: Option<i32> = Some(30);
[INFO] [stdout]    |       ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_maybe_none`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `maybe_none`
[INFO] [stdout]   --> src/day7_match.rs:40:7
[INFO] [stdout]    |
[INFO] [stdout] 40 |   let maybe_none: Option<i32> = None;
[INFO] [stdout]    |       ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_maybe_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `starts_as_null` is assigned to, but never used
[INFO] [stdout]   --> src/day7_match.rs:42:7
[INFO] [stdout]    |
[INFO] [stdout] 42 |   let mut starts_as_null: Option<i64> = None;
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_starts_as_null` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `starts_as_null` is never read
[INFO] [stdout]   --> src/day7_match.rs:45:3
[INFO] [stdout]    |
[INFO] [stdout] 45 |   starts_as_null = Some(39);
[INFO] [stdout]    |   ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `maybe_none`
[INFO] [stdout]   --> src/day7_match.rs:39:7
[INFO] [stdout]    |
[INFO] [stdout] 39 |   let maybe_none: Option<i32> = Some(30);
[INFO] [stdout]    |       ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_maybe_none`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `maybe_none`
[INFO] [stdout]   --> src/day7_match.rs:40:7
[INFO] [stdout]    |
[INFO] [stdout] 40 |   let maybe_none: Option<i32> = None;
[INFO] [stdout]    |       ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_maybe_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `starts_as_null` is assigned to, but never used
[INFO] [stdout]   --> src/day7_match.rs:42:7
[INFO] [stdout]    |
[INFO] [stdout] 42 |   let mut starts_as_null: Option<i64> = None;
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_starts_as_null` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `starts_as_null` is never read
[INFO] [stdout]   --> src/day7_match.rs:45:3
[INFO] [stdout]    |
[INFO] [stdout] 45 |   starts_as_null = Some(39);
[INFO] [stdout]    |   ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.63s
[INFO] running `Command { std: "docker" "inspect" "5ab63bd7ab8c9fe5679ce533f1d4f7afd1314b64770124d24070099747bc76bd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5ab63bd7ab8c9fe5679ce533f1d4f7afd1314b64770124d24070099747bc76bd", kill_on_drop: false }`
[INFO] [stdout] 5ab63bd7ab8c9fe5679ce533f1d4f7afd1314b64770124d24070099747bc76bd