[INFO] cloning repository https://github.com/ZacharyHerfkens/expression_solver_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ZacharyHerfkens/expression_solver_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FZacharyHerfkens%2Fexpression_solver_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FZacharyHerfkens%2Fexpression_solver_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e072cb685c47c4904bf9822e2d6458a763d3e705
[INFO] checking ZacharyHerfkens/expression_solver_rust against master#36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923 for pr-81863
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FZacharyHerfkens%2Fexpression_solver_rust" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ZacharyHerfkens/expression_solver_rust on toolchain 36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ZacharyHerfkens/expression_solver_rust
[INFO] finished tweaking git repo https://github.com/ZacharyHerfkens/expression_solver_rust
[INFO] tweaked toml for git repo https://github.com/ZacharyHerfkens/expression_solver_rust written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/ZacharyHerfkens/expression_solver_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "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] d51edbe153fd85466109c2279501374edc7bc5bed63f44a0d5513e5ea6044b5e
[INFO] running `Command { std: "docker" "start" "-a" "d51edbe153fd85466109c2279501374edc7bc5bed63f44a0d5513e5ea6044b5e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d51edbe153fd85466109c2279501374edc7bc5bed63f44a0d5513e5ea6044b5e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d51edbe153fd85466109c2279501374edc7bc5bed63f44a0d5513e5ea6044b5e", kill_on_drop: false }`
[INFO] [stdout] d51edbe153fd85466109c2279501374edc7bc5bed63f44a0d5513e5ea6044b5e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "check" "--frozen" "--all" "--all-targets" "--message-format=json", 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] 2051d62780ed97692365f2e02b11d86df917f18864b152c0d17f0bd86c0f5449
[INFO] running `Command { std: "docker" "start" "-a" "2051d62780ed97692365f2e02b11d86df917f18864b152c0d17f0bd86c0f5449", kill_on_drop: false }`
[INFO] [stderr]     Checking expression_solver_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Token`
[INFO] [stdout]  --> src/main.rs:2:17
[INFO] [stdout]   |
[INFO] [stdout] 2 | use tokenizer::{Token, Tokenizer};
[INFO] [stdout]   |                 ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Token`
[INFO] [stdout]  --> src/main.rs:2:17
[INFO] [stdout]   |
[INFO] [stdout] 2 | use tokenizer::{Token, Tokenizer};
[INFO] [stdout]   |                 ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> src/tokenizer.rs:31:27
[INFO] [stdout]    |
[INFO] [stdout] 31 |     fn next(&mut self) -> Option<Token> {
[INFO] [stdout]    |        ----               ^^^^^^^^^^^^^ expected enum `Option`, found `()`
[INFO] [stdout]    |        |
[INFO] [stdout]    |        implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout]    |
[INFO] [stdout]    = note:   expected enum `Option<Token>`
[INFO] [stdout]            found unit type `()`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `expression_solver_rust`
[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[E0308]: mismatched types
[INFO] [stdout]   --> src/tokenizer.rs:31:27
[INFO] [stdout]    |
[INFO] [stdout] 31 |     fn next(&mut self) -> Option<Token> {
[INFO] [stdout]    |        ----               ^^^^^^^^^^^^^ expected enum `Option`, found `()`
[INFO] [stdout]    |        |
[INFO] [stdout]    |        implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout]    |
[INFO] [stdout]    = note:   expected enum `Option<Token>`
[INFO] [stdout]            found unit type `()`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "2051d62780ed97692365f2e02b11d86df917f18864b152c0d17f0bd86c0f5449", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2051d62780ed97692365f2e02b11d86df917f18864b152c0d17f0bd86c0f5449", kill_on_drop: false }`
[INFO] [stdout] 2051d62780ed97692365f2e02b11d86df917f18864b152c0d17f0bd86c0f5449