[INFO] cloning repository https://github.com/madhav-madhusoodanan/prolog
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/madhav-madhusoodanan/prolog" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmadhav-madhusoodanan%2Fprolog", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmadhav-madhusoodanan%2Fprolog'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5ddf94bf94c4bfa2714068d5ae6855ef59a541cb
[INFO] checking madhav-madhusoodanan/prolog against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmadhav-madhusoodanan%2Fprolog" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/madhav-madhusoodanan/prolog on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/madhav-madhusoodanan/prolog
[INFO] finished tweaking git repo https://github.com/madhav-madhusoodanan/prolog
[INFO] tweaked toml for git repo https://github.com/madhav-madhusoodanan/prolog written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/madhav-madhusoodanan/prolog already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--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-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5f33285af1dda8ff65a57dd9b29fe4c6e1b8244eb65c473b5688481c2569294b
[INFO] running `Command { std: "docker" "start" "-a" "5f33285af1dda8ff65a57dd9b29fe4c6e1b8244eb65c473b5688481c2569294b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5f33285af1dda8ff65a57dd9b29fe4c6e1b8244eb65c473b5688481c2569294b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5f33285af1dda8ff65a57dd9b29fe4c6e1b8244eb65c473b5688481c2569294b", kill_on_drop: false }`
[INFO] [stdout] 5f33285af1dda8ff65a57dd9b29fe4c6e1b8244eb65c473b5688481c2569294b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5bff01071891b34339c41ca29fb45a3bc31d5d636ab6bd86aeddedbbc7379ec6
[INFO] running `Command { std: "docker" "start" "-a" "5bff01071891b34339c41ca29fb45a3bc31d5d636ab6bd86aeddedbbc7379ec6", kill_on_drop: false }`
[INFO] [stderr]     Checking prolog v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `regex::Regex`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use regex::Regex;
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `lazy_static::lazy_static`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use lazy_static::lazy_static;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `regex::Regex`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use regex::Regex;
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `lazy_static::lazy_static`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use lazy_static::lazy_static;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `line`
[INFO] [stdout]   --> src/main.rs:82:13
[INFO] [stdout]    |
[INFO] [stdout] 82 |         for line in statements {
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_line`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `code`
[INFO] [stdout]   --> src/main.rs:88:21
[INFO] [stdout]    |
[INFO] [stdout] 88 |     fn query(&self, code: &String) -> Result<String, ParseError> {
[INFO] [stdout]    |                     ^^^^ help: if this is intentional, prefix it with an underscore: `_code`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:89:13
[INFO] [stdout]    |
[INFO] [stdout] 89 |         let mut result = String::new();
[INFO] [stdout]    |             ----^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tokens`
[INFO] [stdout]   --> src/main.rs:96:13
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let mut tokens: Vec<Token> = Vec::new();
[INFO] [stdout]    |             ^^^^^^ help: if this is intentional, prefix it with an underscore: `_tokens`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:96:9
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let mut tokens: Vec<Token> = Vec::new();
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `line`
[INFO] [stdout]   --> src/main.rs:82:13
[INFO] [stdout]    |
[INFO] [stdout] 82 |         for line in statements {
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_line`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Relation`, `Variable`, and `Constant` are never constructed
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum Token {
[INFO] [stdout]   |      ----- variants in this enum
[INFO] [stdout] 4 |     Relation(String, Vec<Box<Token>>, bool), 
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 5 |     Variable(String),
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 6 |     Constant(String),
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `represent` is never used
[INFO] [stdout]  --> src/main.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | impl Token {
[INFO] [stdout]   | ---------- method in this implementation
[INFO] [stdout] 9 |     fn represent(&self, level: usize) -> String {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `ParseError` is never used
[INFO] [stdout]   --> src/main.rs:35:6
[INFO] [stdout]    |
[INFO] [stdout] 35 | enum ParseError {
[INFO] [stdout]    |      ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Operator` is never used
[INFO] [stdout]   --> src/main.rs:39:6
[INFO] [stdout]    |
[INFO] [stdout] 39 | enum Operator {
[INFO] [stdout]    |      ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `represent` is never used
[INFO] [stdout]   --> src/main.rs:46:8
[INFO] [stdout]    |
[INFO] [stdout] 45 | impl Operator {
[INFO] [stdout]    | ------------- method in this implementation
[INFO] [stdout] 46 |     fn represent(&self) -> String {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Thing` is never used
[INFO] [stdout]   --> src/main.rs:55:6
[INFO] [stdout]    |
[INFO] [stdout] 55 | enum Thing {
[INFO] [stdout]    |      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `represent` is never used
[INFO] [stdout]   --> src/main.rs:61:8
[INFO] [stdout]    |
[INFO] [stdout] 60 | impl Thing {
[INFO] [stdout]    | ---------- method in this implementation
[INFO] [stdout] 61 |     fn represent(&self, _: usize) -> String {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Evaluator` is never constructed
[INFO] [stdout]   --> src/main.rs:68:8
[INFO] [stdout]    |
[INFO] [stdout] 68 | struct Evaluator {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `parse`, and `query` are never used
[INFO] [stdout]   --> src/main.rs:72:8
[INFO] [stdout]    |
[INFO] [stdout] 71 | impl Evaluator {
[INFO] [stdout]    | -------------- associated items in this implementation
[INFO] [stdout] 72 |     fn new() -> Evaluator {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 77 |     fn parse(&self, code: &String) -> Result<&Vec<Thing>, ParseError> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 88 |     fn query(&self, code: &String) -> Result<String, ParseError> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `code`
[INFO] [stdout]   --> src/main.rs:88:21
[INFO] [stdout]    |
[INFO] [stdout] 88 |     fn query(&self, code: &String) -> Result<String, ParseError> {
[INFO] [stdout]    |                     ^^^^ help: if this is intentional, prefix it with an underscore: `_code`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:89:13
[INFO] [stdout]    |
[INFO] [stdout] 89 |         let mut result = String::new();
[INFO] [stdout]    |             ----^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tokens`
[INFO] [stdout]   --> src/main.rs:96:13
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let mut tokens: Vec<Token> = Vec::new();
[INFO] [stdout]    |             ^^^^^^ help: if this is intentional, prefix it with an underscore: `_tokens`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:96:9
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let mut tokens: Vec<Token> = Vec::new();
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `2` is never read
[INFO] [stdout]  --> src/main.rs:4:39
[INFO] [stdout]   |
[INFO] [stdout] 4 |     Relation(String, Vec<Box<Token>>, bool), 
[INFO] [stdout]   |     -------- field in this variant    ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 4 |     Relation(String, Vec<Box<Token>>, ()), 
[INFO] [stdout]   |                                       ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Variable` is never constructed
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum Token {
[INFO] [stdout]   |      ----- variant in this enum
[INFO] [stdout] 4 |     Relation(String, Vec<Box<Token>>, bool), 
[INFO] [stdout] 5 |     Variable(String),
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `CantRead` is never constructed
[INFO] [stdout]   --> src/main.rs:36:5
[INFO] [stdout]    |
[INFO] [stdout] 35 | enum ParseError {
[INFO] [stdout]    |      ---------- variant in this enum
[INFO] [stdout] 36 |     CantRead
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `ParseError` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `If`, `And`, and `Or` are never constructed
[INFO] [stdout]   --> src/main.rs:40:5
[INFO] [stdout]    |
[INFO] [stdout] 39 | enum Operator {
[INFO] [stdout]    |      -------- variants in this enum
[INFO] [stdout] 40 |     If,    // lhs, rhs
[INFO] [stdout]    |     ^^
[INFO] [stdout] 41 |     And,   // lhs, rhs
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 42 |     Or,
[INFO] [stdout]    |     ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Op` is never constructed
[INFO] [stdout]   --> src/main.rs:56:5
[INFO] [stdout]    |
[INFO] [stdout] 55 | enum Thing {
[INFO] [stdout]    |      ----- variant in this enum
[INFO] [stdout] 56 |     Op(Operator),
[INFO] [stdout]    |     ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 16 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.14s
[INFO] running `Command { std: "docker" "inspect" "5bff01071891b34339c41ca29fb45a3bc31d5d636ab6bd86aeddedbbc7379ec6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5bff01071891b34339c41ca29fb45a3bc31d5d636ab6bd86aeddedbbc7379ec6", kill_on_drop: false }`
[INFO] [stdout] 5bff01071891b34339c41ca29fb45a3bc31d5d636ab6bd86aeddedbbc7379ec6