[INFO] cloning repository https://github.com/blueish/rlox
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/blueish/rlox" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fblueish%2Frlox", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fblueish%2Frlox'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b4e2d5e1dcbce74d6fb0d24bebe7c39674cec91f
[INFO] checking blueish/rlox against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fblueish%2Frlox" "/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/blueish/rlox 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/blueish/rlox
[INFO] finished tweaking git repo https://github.com/blueish/rlox
[INFO] tweaked toml for git repo https://github.com/blueish/rlox written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/blueish/rlox 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] 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] 991990d3791608c0d093f81ab73699b74bd0d415354d2a5e52e0c24d948dfb4f
[INFO] running `Command { std: "docker" "start" "-a" "991990d3791608c0d093f81ab73699b74bd0d415354d2a5e52e0c24d948dfb4f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "991990d3791608c0d093f81ab73699b74bd0d415354d2a5e52e0c24d948dfb4f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "991990d3791608c0d093f81ab73699b74bd0d415354d2a5e52e0c24d948dfb4f", kill_on_drop: false }`
[INFO] [stdout] 991990d3791608c0d093f81ab73699b74bd0d415354d2a5e52e0c24d948dfb4f
[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] 31743e6f7fe8dcaa245961fdf86830ac940638798209ca9660838cfda9bd04d9
[INFO] running `Command { std: "docker" "start" "-a" "31743e6f7fe8dcaa245961fdf86830ac940638798209ca9660838cfda9bd04d9", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking quick-error v1.2.2
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]     Checking termcolor v1.0.5
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking aho-corasick v0.7.6
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking interpreter v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `Option` is imported redundantly
[INFO] [stdout]  --> src/token.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::option::Option;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `Option` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp`
[INFO] [stdout]  --> src/callable.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/value.rs:12:21
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<dyn Callable>>),
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/mod.rs:16:33
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T;
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:13:21
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for Callable {
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for dyn Callable {
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Option` is imported redundantly
[INFO] [stdout]  --> src/token.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::option::Option;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `Option` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Token` is imported redundantly
[INFO] [stdout]    --> src/parser.rs:489:9
[INFO] [stdout]     |
[INFO] [stdout] 488 |     use super::*;
[INFO] [stdout]     |         -------- the item `Token` is already imported here
[INFO] [stdout] 489 |     use crate::token::Token;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `StringLit`
[INFO] [stdout]    --> src/parser.rs:490:49
[INFO] [stdout]     |
[INFO] [stdout] 490 |     use crate::ast::literals::Literal::{Number, StringLit};
[INFO] [stdout]     |                                                 ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `ValueExpr` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:34
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `ValueExpr` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Unary` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:45
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Unary` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                             ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Binary` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:52
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Binary` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                                    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Grouping` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:60
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Grouping` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                                            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Value` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:349:9
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Value` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout] 349 |     use crate::value::Value;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp`
[INFO] [stdout]  --> src/callable.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:19:20
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for Callable {
[INFO] [stdout]    |                    ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for dyn Callable {
[INFO] [stdout]    |                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/expr.rs:18:33
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T {
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T {
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/value.rs:12:21
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<dyn Callable>>),
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/mod.rs:16:33
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T;
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:13:21
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for Callable {
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for dyn Callable {
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:19:20
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for Callable {
[INFO] [stdout]    |                    ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for dyn Callable {
[INFO] [stdout]    |                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/expr.rs:18:33
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T {
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T {
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `accept` is never used
[INFO] [stdout]   --> src/ast/mod.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub trait Node {
[INFO] [stdout]    |           ---- method in this trait
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `lexeme` is never read
[INFO] [stdout]   --> src/parser.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct ParseError {
[INFO] [stdout]    |            ---------- field in this struct
[INFO] [stdout] 14 |     line: usize,
[INFO] [stdout] 15 |     lexeme: String,
[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: field `msg` is never read
[INFO] [stdout]   --> src/interp/interpreter.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct InterpErr {
[INFO] [stdout]    |            --------- field in this struct
[INFO] [stdout] 14 |     msg: String,
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `InterpErr` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `ClosureV` is never constructed
[INFO] [stdout]   --> src/value.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub enum Value {
[INFO] [stdout]    |          ----- variant in this enum
[INFO] [stdout] ...
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Value` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/interp/interpreter.rs:266:25
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         let _ = std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `accept` is never used
[INFO] [stdout]   --> src/ast/mod.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub trait Node {
[INFO] [stdout]    |           ---- method in this trait
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `lexeme` is never read
[INFO] [stdout]   --> src/parser.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct ParseError {
[INFO] [stdout]    |            ---------- field in this struct
[INFO] [stdout] 14 |     line: usize,
[INFO] [stdout] 15 |     lexeme: String,
[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: function `init` is never used
[INFO] [stdout]    --> src/parser.rs:492:8
[INFO] [stdout]     |
[INFO] [stdout] 492 |     fn init() {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `msg` is never read
[INFO] [stdout]   --> src/interp/interpreter.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct InterpErr {
[INFO] [stdout]    |            --------- field in this struct
[INFO] [stdout] 14 |     msg: String,
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `InterpErr` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `ClosureV` is never constructed
[INFO] [stdout]   --> src/value.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub enum Value {
[INFO] [stdout]    |          ----- variant in this enum
[INFO] [stdout] ...
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Value` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/interp/interpreter.rs:266:25
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         let _ = std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.75s
[INFO] running `Command { std: "docker" "inspect" "31743e6f7fe8dcaa245961fdf86830ac940638798209ca9660838cfda9bd04d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31743e6f7fe8dcaa245961fdf86830ac940638798209ca9660838cfda9bd04d9", kill_on_drop: false }`
[INFO] [stdout] 31743e6f7fe8dcaa245961fdf86830ac940638798209ca9660838cfda9bd04d9
[INFO] checking blueish/rlox against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fblueish%2Frlox" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/blueish/rlox on toolchain 645bb72776a6a56a1a8f52631a44bd082b2ba509
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/blueish/rlox
[INFO] finished tweaking git repo https://github.com/blueish/rlox
[INFO] tweaked toml for git repo https://github.com/blueish/rlox written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/blueish/rlox 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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] df951b3eef85ffd4fbfc5570d936e1d5aa330385a4d9e4567331a5f6cf034ff5
[INFO] running `Command { std: "docker" "start" "-a" "df951b3eef85ffd4fbfc5570d936e1d5aa330385a4d9e4567331a5f6cf034ff5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "df951b3eef85ffd4fbfc5570d936e1d5aa330385a4d9e4567331a5f6cf034ff5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "df951b3eef85ffd4fbfc5570d936e1d5aa330385a4d9e4567331a5f6cf034ff5", kill_on_drop: false }`
[INFO] [stdout] df951b3eef85ffd4fbfc5570d936e1d5aa330385a4d9e4567331a5f6cf034ff5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f68966e7ec891004cb5d776adf38c9596e11bad46700bc87eeaddfe7c942e228
[INFO] running `Command { std: "docker" "start" "-a" "f68966e7ec891004cb5d776adf38c9596e11bad46700bc87eeaddfe7c942e228", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking quick-error v1.2.2
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking termcolor v1.0.5
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking aho-corasick v0.7.6
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking interpreter v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `Option` is imported redundantly
[INFO] [stdout]  --> src/token.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::option::Option;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/645bb72776a6a56a1a8f52631a44bd082b2ba509/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `Option` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Option` is imported redundantly
[INFO] [stdout]  --> src/token.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::option::Option;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/645bb72776a6a56a1a8f52631a44bd082b2ba509/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `Option` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Token` is imported redundantly
[INFO] [stdout]    --> src/parser.rs:489:9
[INFO] [stdout]     |
[INFO] [stdout] 488 |     use super::*;
[INFO] [stdout]     |         -------- the item `Token` is already imported here
[INFO] [stdout] 489 |     use crate::token::Token;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp`
[INFO] [stdout]  --> src/callable.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `StringLit`
[INFO] [stdout]    --> src/parser.rs:490:49
[INFO] [stdout]     |
[INFO] [stdout] 490 |     use crate::ast::literals::Literal::{Number, StringLit};
[INFO] [stdout]     |                                                 ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `ValueExpr` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:34
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `ValueExpr` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Unary` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:45
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Unary` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                             ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Binary` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:52
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Binary` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                                    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Grouping` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:348:60
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Grouping` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout]     |                                                            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Value` is imported redundantly
[INFO] [stdout]    --> src/interp/interpreter.rs:349:9
[INFO] [stdout]     |
[INFO] [stdout] 347 |     use super::*;
[INFO] [stdout]     |         -------- the item `Value` is already imported here
[INFO] [stdout] 348 |     use crate::ast::expr::Expr::{ValueExpr, Unary, Binary, Grouping};
[INFO] [stdout] 349 |     use crate::value::Value;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cmp`
[INFO] [stdout]  --> src/callable.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cmp;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/value.rs:12:21
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<dyn Callable>>),
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/mod.rs:16:33
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T;
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:13:21
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for Callable {
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for dyn Callable {
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:19:20
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for Callable {
[INFO] [stdout]    |                    ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for dyn Callable {
[INFO] [stdout]    |                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/value.rs:12:21
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 12 |     ClosureV(Rc<Box<dyn Callable>>),
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/mod.rs:16:33
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T;
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:13:21
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for Callable {
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl fmt::Debug for dyn Callable {
[INFO] [stdout]    |                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/callable.rs:19:20
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for Callable {
[INFO] [stdout]    |                    ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 19 | impl PartialEq for dyn Callable {
[INFO] [stdout]    |                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/expr.rs:18:33
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T {
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T {
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ast/expr.rs:18:33
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T {
[INFO] [stdout]    |                                 ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn accept<T>(&self, v: &mut dyn Visitor<T>) -> T {
[INFO] [stdout]    |                                 +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `accept` is never used
[INFO] [stdout]   --> src/ast/mod.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub trait Node {
[INFO] [stdout]    |           ---- method in this trait
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `lexeme` is never read
[INFO] [stdout]   --> src/parser.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct ParseError {
[INFO] [stdout]    |            ---------- field in this struct
[INFO] [stdout] 14 |     line: usize,
[INFO] [stdout] 15 |     lexeme: String,
[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: field `msg` is never read
[INFO] [stdout]   --> src/interp/interpreter.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct InterpErr {
[INFO] [stdout]    |            --------- field in this struct
[INFO] [stdout] 14 |     msg: String,
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `InterpErr` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `ClosureV` is never constructed
[INFO] [stdout]   --> src/value.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub enum Value {
[INFO] [stdout]    |          ----- variant in this enum
[INFO] [stdout] ...
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Value` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/interp/interpreter.rs:266:25
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         let _ = std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `accept` is never used
[INFO] [stdout]   --> src/ast/mod.rs:16:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub trait Node {
[INFO] [stdout]    |           ---- method in this trait
[INFO] [stdout] 16 |     fn accept<T>(&self, v: &mut Visitor<T>) -> T;
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `lexeme` is never read
[INFO] [stdout]   --> src/parser.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct ParseError {
[INFO] [stdout]    |            ---------- field in this struct
[INFO] [stdout] 14 |     line: usize,
[INFO] [stdout] 15 |     lexeme: String,
[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: function `init` is never used
[INFO] [stdout]    --> src/parser.rs:492:8
[INFO] [stdout]     |
[INFO] [stdout] 492 |     fn init() {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `msg` is never read
[INFO] [stdout]   --> src/interp/interpreter.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub struct InterpErr {
[INFO] [stdout]    |            --------- field in this struct
[INFO] [stdout] 14 |     msg: String,
[INFO] [stdout]    |     ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `InterpErr` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `ClosureV` is never constructed
[INFO] [stdout]   --> src/value.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub enum Value {
[INFO] [stdout]    |          ----- variant in this enum
[INFO] [stdout] ...
[INFO] [stdout] 12 |     ClosureV(Rc<Box<Callable>>),
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Value` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/interp/interpreter.rs:266:25
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 266 |                         let _ = std::mem::replace(&mut self.environment, env);
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.45s
[INFO] running `Command { std: "docker" "inspect" "f68966e7ec891004cb5d776adf38c9596e11bad46700bc87eeaddfe7c942e228", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f68966e7ec891004cb5d776adf38c9596e11bad46700bc87eeaddfe7c942e228", kill_on_drop: false }`
[INFO] [stdout] f68966e7ec891004cb5d776adf38c9596e11bad46700bc87eeaddfe7c942e228