[INFO] cloning repository https://github.com/yportne13/type-inference-by-example-in-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/yportne13/type-inference-by-example-in-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyportne13%2Ftype-inference-by-example-in-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyportne13%2Ftype-inference-by-example-in-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3818e82f8049f1b7704081483e74c9bd4a988841
[INFO] checking yportne13/type-inference-by-example-in-rust against 1.95.0 for pr-155915
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyportne13%2Ftype-inference-by-example-in-rust" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/yportne13/type-inference-by-example-in-rust
[INFO] finished tweaking git repo https://github.com/yportne13/type-inference-by-example-in-rust
[INFO] tweaked toml for git repo https://github.com/yportne13/type-inference-by-example-in-rust written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/yportne13/type-inference-by-example-in-rust on toolchain 1.95.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.95.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/yportne13/type-inference-by-example-in-rust 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" "+1.95.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cf0dbf37a214cb098d940b448ecb10384fbba49e2410c1063e9246d67ecb3519
[INFO] running `Command { std: "docker" "start" "-a" "cf0dbf37a214cb098d940b448ecb10384fbba49e2410c1063e9246d67ecb3519", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cf0dbf37a214cb098d940b448ecb10384fbba49e2410c1063e9246d67ecb3519", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cf0dbf37a214cb098d940b448ecb10384fbba49e2410c1063e9246d67ecb3519", kill_on_drop: false }`
[INFO] [stdout] cf0dbf37a214cb098d940b448ecb10384fbba49e2410c1063e9246d67ecb3519
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6f32a5cff585bbb9a79bcdcac19c03ec18287d9faf0995a3746f84660547468f
[INFO] running `Command { std: "docker" "start" "-a" "6f32a5cff585bbb9a79bcdcac19c03ec18287d9faf0995a3746f84660547468f", kill_on_drop: false }`
[INFO] [stderr]     Checking hindley_milner v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(pattern)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Maybe` and `maybe`
[INFO] [stdout]  --> src/parser/mod.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use core::{maybe, Maybe, Parser, Span};
[INFO] [stdout]   |            ^^^^^  ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(pattern)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Maybe` and `maybe`
[INFO] [stdout]  --> src/parser/mod.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use core::{maybe, Maybe, Parser, Span};
[INFO] [stdout]   |            ^^^^^  ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `endline`
[INFO] [stdout]    --> src/parser/lex.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let endline = pmatch("\n").map(|x| x.map(|y| (y, EndLine)));
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_endline`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fun`
[INFO] [stdout]    --> src/parser/mod.rs:176:17
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let (input, fun) = kw(TokenKind::FunKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^ help: if this is intentional, prefix it with an underscore: `_fun`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arrow`
[INFO] [stdout]    --> src/parser/mod.rs:178:17
[INFO] [stdout]     |
[INFO] [stdout] 178 |     let (input, arrow) = kw(TokenKind::Arrow).parse(input)?;
[INFO] [stdout]     |                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_arrow`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `if_kw`
[INFO] [stdout]    --> src/parser/mod.rs:187:17
[INFO] [stdout]     |
[INFO] [stdout] 187 |     let (input, if_kw) = kw(TokenKind::IfKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_if_kw`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `then_kw`
[INFO] [stdout]    --> src/parser/mod.rs:189:17
[INFO] [stdout]     |
[INFO] [stdout] 189 |     let (input, then_kw) = kw(TokenKind::ThenKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_then_kw`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `else_kw`
[INFO] [stdout]    --> src/parser/mod.rs:191:17
[INFO] [stdout]     |
[INFO] [stdout] 191 |     let (input, else_kw) = kw(TokenKind::ElseKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_else_kw`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `keyword`
[INFO] [stdout]    --> src/parser/mod.rs:212:17
[INFO] [stdout]     |
[INFO] [stdout] 212 |     let (input, keyword) = kw(TokenKind::LetKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_keyword`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `eq`
[INFO] [stdout]    --> src/parser/mod.rs:214:17
[INFO] [stdout]     |
[INFO] [stdout] 214 |     let (input, eq) = kw(TokenKind::Eq).parse(input)?;
[INFO] [stdout]     |                 ^^ help: if this is intentional, prefix it with an underscore: `_eq`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> src/part5/mod.rs:91:16
[INFO] [stdout]    |
[INFO] [stdout] 91 |             if let Constraint::Equality(t1, t2) = constraint {
[INFO] [stdout]    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]    --> src/part6/mod.rs:183:16
[INFO] [stdout]     |
[INFO] [stdout] 183 |             if let Constraint::CEquality(t1, t2) = constraint {
[INFO] [stdout]     |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]     = help: consider replacing the `if let` with a `let`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hindley_milner` (bin "hindley_milner" test) due to 1 previous error; 11 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused variable: `endline`
[INFO] [stdout]    --> src/parser/lex.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let endline = pmatch("\n").map(|x| x.map(|y| (y, EndLine)));
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_endline`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fun`
[INFO] [stdout]    --> src/parser/mod.rs:176:17
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let (input, fun) = kw(TokenKind::FunKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^ help: if this is intentional, prefix it with an underscore: `_fun`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arrow`
[INFO] [stdout]    --> src/parser/mod.rs:178:17
[INFO] [stdout]     |
[INFO] [stdout] 178 |     let (input, arrow) = kw(TokenKind::Arrow).parse(input)?;
[INFO] [stdout]     |                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_arrow`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `if_kw`
[INFO] [stdout]    --> src/parser/mod.rs:187:17
[INFO] [stdout]     |
[INFO] [stdout] 187 |     let (input, if_kw) = kw(TokenKind::IfKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_if_kw`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `then_kw`
[INFO] [stdout]    --> src/parser/mod.rs:189:17
[INFO] [stdout]     |
[INFO] [stdout] 189 |     let (input, then_kw) = kw(TokenKind::ThenKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_then_kw`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `else_kw`
[INFO] [stdout]    --> src/parser/mod.rs:191:17
[INFO] [stdout]     |
[INFO] [stdout] 191 |     let (input, else_kw) = kw(TokenKind::ElseKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_else_kw`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `keyword`
[INFO] [stdout]    --> src/parser/mod.rs:212:17
[INFO] [stdout]     |
[INFO] [stdout] 212 |     let (input, keyword) = kw(TokenKind::LetKeyword).parse(input)?;
[INFO] [stdout]     |                 ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_keyword`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `eq`
[INFO] [stdout]    --> src/parser/mod.rs:214:17
[INFO] [stdout]     |
[INFO] [stdout] 214 |     let (input, eq) = kw(TokenKind::Eq).parse(input)?;
[INFO] [stdout]     |                 ^^ help: if this is intentional, prefix it with an underscore: `_eq`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> src/part5/mod.rs:91:16
[INFO] [stdout]    |
[INFO] [stdout] 91 |             if let Constraint::Equality(t1, t2) = constraint {
[INFO] [stdout]    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]    --> src/part6/mod.rs:183:16
[INFO] [stdout]     |
[INFO] [stdout] 183 |             if let Constraint::CEquality(t1, t2) = constraint {
[INFO] [stdout]     |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]     = help: consider replacing the `if let` with a `let`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hindley_milner` (bin "hindley_milner") due to 1 previous error; 11 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "6f32a5cff585bbb9a79bcdcac19c03ec18287d9faf0995a3746f84660547468f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f32a5cff585bbb9a79bcdcac19c03ec18287d9faf0995a3746f84660547468f", kill_on_drop: false }`
[INFO] [stdout] 6f32a5cff585bbb9a79bcdcac19c03ec18287d9faf0995a3746f84660547468f
