[INFO] cloning repository https://github.com/neverRare/butter
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/neverRare/butter" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FneverRare%2Fbutter", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FneverRare%2Fbutter'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 34d32b4d368b1dee06f99151bb9a9f43fb249889
[INFO] checking neverRare/butter against master#db1fb85cff63ad5fffe435e17128f99f9e1d970c for pr-89056
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FneverRare%2Fbutter" "/workspace/builds/worker-90/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-90/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/neverRare/butter on toolchain db1fb85cff63ad5fffe435e17128f99f9e1d970c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/neverRare/butter
[INFO] finished tweaking git repo https://github.com/neverRare/butter
[INFO] tweaked toml for git repo https://github.com/neverRare/butter written to /workspace/builds/worker-90/source/Cargo.toml
[INFO] crate git repo https://github.com/neverRare/butter already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "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-90/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-90/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 56a8fcce36316b7be2c4c40f1f528e20bbde27715fbc0d29967184af7902c6c4
[INFO] running `Command { std: "docker" "start" "-a" "56a8fcce36316b7be2c4c40f1f528e20bbde27715fbc0d29967184af7902c6c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "56a8fcce36316b7be2c4c40f1f528e20bbde27715fbc0d29967184af7902c6c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56a8fcce36316b7be2c4c40f1f528e20bbde27715fbc0d29967184af7902c6c4", kill_on_drop: false }`
[INFO] [stdout] 56a8fcce36316b7be2c4c40f1f528e20bbde27715fbc0d29967184af7902c6c4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-90/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-90/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9f6897b13934d47484ba78b80c0755d2d884ff660ab0e33cd9ccc3659a9a626c
[INFO] running `Command { std: "docker" "start" "-a" "9f6897b13934d47484ba78b80c0755d2d884ff660ab0e33cd9ccc3659a9a626c", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.29
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling libc v0.2.101
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]     Checking hir v0.1.0 (/opt/rustwide/workdir/hir)
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]     Checking bytes v1.1.0
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking type-system v0.1.0 (/opt/rustwide/workdir/type-system)
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stdout] warning: unused variable: `statements`
[INFO] [stdout]    --> type-system/src/lib.rs:234:14
[INFO] [stdout]     |
[INFO] [stdout] 234 | pub fn infer(statements: Vec<Statement<()>>) -> Result<Vec<Statement<Type>>, TypeError> {
[INFO] [stdout]     |              ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_statements`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `statements`
[INFO] [stdout]    --> type-system/src/lib.rs:234:14
[INFO] [stdout]     |
[INFO] [stdout] 234 | pub fn infer(statements: Vec<Statement<()>>) -> Result<Vec<Statement<Type>>, TypeError> {
[INFO] [stdout]     |              ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_statements`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `kind`
[INFO] [stdout]    --> type-system/src/ty.rs:162:8
[INFO] [stdout]     |
[INFO] [stdout] 162 |     fn kind(&self) -> Kind {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `free_vars`
[INFO] [stdout]    --> type-system/src/ty.rs:168:8
[INFO] [stdout]     |
[INFO] [stdout] 168 |     fn free_vars(&self) -> HashSet<KindedVar<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `free_vars`
[INFO] [stdout]    --> type-system/src/ty.rs:187:8
[INFO] [stdout]     |
[INFO] [stdout] 187 |     fn free_vars(&self) -> HashSet<KindedVar<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `substitute`
[INFO] [stdout]    --> type-system/src/ty.rs:194:8
[INFO] [stdout]     |
[INFO] [stdout] 194 |     fn substitute(&mut self, subs: &Subs<'a>) -> Result<(), TypeError> {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `filter_off`
[INFO] [stdout]    --> type-system/src/ty.rs:244:8
[INFO] [stdout]     |
[INFO] [stdout] 244 |     fn filter_off(&mut self, vars: &HashSet<KindedVar<'a>>) {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `hashmap_mut`
[INFO] [stdout]    --> type-system/src/ty.rs:276:8
[INFO] [stdout]     |
[INFO] [stdout] 276 |     fn hashmap_mut(&mut self) -> &mut HashMap<Var<'a>, Scheme<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `remove`
[INFO] [stdout]    --> type-system/src/ty.rs:283:8
[INFO] [stdout]     |
[INFO] [stdout] 283 |     fn remove(&mut self, var: Var<'a>) {
[INFO] [stdout]     |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `free_vars`
[INFO] [stdout]    --> type-system/src/ty.rs:286:8
[INFO] [stdout]     |
[INFO] [stdout] 286 |     fn free_vars(&self) -> HashSet<KindedVar<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `substitute`
[INFO] [stdout]    --> type-system/src/ty.rs:292:8
[INFO] [stdout]     |
[INFO] [stdout] 292 |     fn substitute(&mut self, subs: &Subs<'a>) -> Result<(), TypeError> {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `generalize`
[INFO] [stdout]    --> type-system/src/ty.rs:298:8
[INFO] [stdout]     |
[INFO] [stdout] 298 |     fn generalize(&self, ty: Type<'a>) -> Scheme<'a> {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `kind`
[INFO] [stdout]    --> type-system/src/ty.rs:162:8
[INFO] [stdout]     |
[INFO] [stdout] 162 |     fn kind(&self) -> Kind {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `free_vars`
[INFO] [stdout]    --> type-system/src/ty.rs:168:8
[INFO] [stdout]     |
[INFO] [stdout] 168 |     fn free_vars(&self) -> HashSet<KindedVar<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `free_vars`
[INFO] [stdout]    --> type-system/src/ty.rs:187:8
[INFO] [stdout]     |
[INFO] [stdout] 187 |     fn free_vars(&self) -> HashSet<KindedVar<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `substitute`
[INFO] [stdout]    --> type-system/src/ty.rs:194:8
[INFO] [stdout]     |
[INFO] [stdout] 194 |     fn substitute(&mut self, subs: &Subs<'a>) -> Result<(), TypeError> {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `filter_off`
[INFO] [stdout]    --> type-system/src/ty.rs:244:8
[INFO] [stdout]     |
[INFO] [stdout] 244 |     fn filter_off(&mut self, vars: &HashSet<KindedVar<'a>>) {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `hashmap_mut`
[INFO] [stdout]    --> type-system/src/ty.rs:276:8
[INFO] [stdout]     |
[INFO] [stdout] 276 |     fn hashmap_mut(&mut self) -> &mut HashMap<Var<'a>, Scheme<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `remove`
[INFO] [stdout]    --> type-system/src/ty.rs:283:8
[INFO] [stdout]     |
[INFO] [stdout] 283 |     fn remove(&mut self, var: Var<'a>) {
[INFO] [stdout]     |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `free_vars`
[INFO] [stdout]    --> type-system/src/ty.rs:286:8
[INFO] [stdout]     |
[INFO] [stdout] 286 |     fn free_vars(&self) -> HashSet<KindedVar<'a>> {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `substitute`
[INFO] [stdout]    --> type-system/src/ty.rs:292:8
[INFO] [stdout]     |
[INFO] [stdout] 292 |     fn substitute(&mut self, subs: &Subs<'a>) -> Result<(), TypeError> {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `generalize`
[INFO] [stdout]    --> type-system/src/ty.rs:298:8
[INFO] [stdout]     |
[INFO] [stdout] 298 |     fn generalize(&self, ty: Type<'a>) -> Scheme<'a> {
[INFO] [stdout]     |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking combine v4.6.1
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]    Compiling structopt-derive v0.4.16
[INFO] [stderr]     Checking parser v0.1.0 (/opt/rustwide/workdir/parser)
[INFO] [stderr]     Checking structopt v0.3.23
[INFO] [stderr]     Checking butter v0.1.0 (/opt/rustwide/workdir/cli)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 55.45s
[INFO] running `Command { std: "docker" "inspect" "9f6897b13934d47484ba78b80c0755d2d884ff660ab0e33cd9ccc3659a9a626c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9f6897b13934d47484ba78b80c0755d2d884ff660ab0e33cd9ccc3659a9a626c", kill_on_drop: false }`
[INFO] [stdout] 9f6897b13934d47484ba78b80c0755d2d884ff660ab0e33cd9ccc3659a9a626c