[INFO] cloning repository https://github.com/Malmz/pascal-parser-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Malmz/pascal-parser-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMalmz%2Fpascal-parser-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMalmz%2Fpascal-parser-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 10481f4d90875a836580176c277d812a279c01b4
[INFO] testing Malmz/pascal-parser-rs against beta-2023-04-20 for beta-1.70-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMalmz%2Fpascal-parser-rs" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Malmz/pascal-parser-rs on toolchain beta-2023-04-20
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2023-04-20" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Malmz/pascal-parser-rs
[INFO] finished tweaking git repo https://github.com/Malmz/pascal-parser-rs
[INFO] tweaked toml for git repo https://github.com/Malmz/pascal-parser-rs written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/Malmz/pascal-parser-rs 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" "+beta-2023-04-20" "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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2023-04-20" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5b34b648e9cf4229b84084d98243805829a6f2c7f004898d5a11770d997a0a98
[INFO] running `Command { std: "docker" "start" "-a" "5b34b648e9cf4229b84084d98243805829a6f2c7f004898d5a11770d997a0a98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5b34b648e9cf4229b84084d98243805829a6f2c7f004898d5a11770d997a0a98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5b34b648e9cf4229b84084d98243805829a6f2c7f004898d5a11770d997a0a98", kill_on_drop: false }`
[INFO] [stdout] 5b34b648e9cf4229b84084d98243805829a6f2c7f004898d5a11770d997a0a98
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2023-04-20" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b5b19fd6f9ca5f024b021ec3b2bcaedf1dfe16bf96d9522e2498ce60e81911dc
[INFO] running `Command { std: "docker" "start" "-a" "b5b19fd6f9ca5f024b021ec3b2bcaedf1dfe16bf96d9522e2498ce60e81911dc", kill_on_drop: false }`
[INFO] [stderr]    Compiling parser v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/main.rs:1:28
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(slice_patterns, advanced_slice_patterns)]
[INFO] [stdout]   |                            ^^^^^^^^^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: merged into `#![feature(slice_patterns)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: expected expression, found `=>`
[INFO] [stdout]   --> src/parser/lexer2.rs:36:33
[INFO] [stdout]    |
[INFO] [stdout] 36 |             Some(val) if val != => {
[INFO] [stdout]    |                                 ^^ expected expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(slice_patterns, advanced_slice_patterns)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `slice_patterns` has been stable since `1.42.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `slice_patterns` has been stable since 1.42.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(slice_patterns, advanced_slice_patterns)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/binop.rs:10:12
[INFO] [stdout]    |
[INFO] [stdout] 10 |     l: Box<Node>,
[INFO] [stdout]    |            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 |     l: Box<dyn Node>,
[INFO] [stdout]    |            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/binop.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 |     r: Box<Node>
[INFO] [stdout]    |            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 11 |     r: Box<dyn Node>
[INFO] [stdout]    |            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/unaryop.rs:10:14
[INFO] [stdout]    |
[INFO] [stdout] 10 |     val: Box<Node>,
[INFO] [stdout]    |              ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 |     val: Box<dyn Node>,
[INFO] [stdout]    |              +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/mod.rs:16:36
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept(&self, visitor: &mut AstVisitor);
[INFO] [stdout]    |                                    ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn accept(&self, visitor: &mut dyn AstVisitor);
[INFO] [stdout]    |                                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/leaf.rs:24:36
[INFO] [stdout]    |
[INFO] [stdout] 24 |     fn accept(&self, visitor: &mut AstVisitor) {
[INFO] [stdout]    |                                    ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 24 |     fn accept(&self, visitor: &mut dyn AstVisitor) {
[INFO] [stdout]    |                                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/binop.rs:15:43
[INFO] [stdout]    |
[INFO] [stdout] 15 |     pub fn new(op: BinOperator, left: Box<Node>, right: Box<Node>) -> Box<Self> {
[INFO] [stdout]    |                                           ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 15 |     pub fn new(op: BinOperator, left: Box<dyn Node>, right: Box<Node>) -> Box<Self> {
[INFO] [stdout]    |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/binop.rs:15:61
[INFO] [stdout]    |
[INFO] [stdout] 15 |     pub fn new(op: BinOperator, left: Box<Node>, right: Box<Node>) -> Box<Self> {
[INFO] [stdout]    |                                                             ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 15 |     pub fn new(op: BinOperator, left: Box<Node>, right: Box<dyn Node>) -> Box<Self> {
[INFO] [stdout]    |                                                             +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/binop.rs:27:28
[INFO] [stdout]    |
[INFO] [stdout] 27 |     pub fn left(&self) -> &Node {
[INFO] [stdout]    |                            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 27 |     pub fn left(&self) -> &dyn Node {
[INFO] [stdout]    |                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/binop.rs:31:29
[INFO] [stdout]    |
[INFO] [stdout] 31 |     pub fn right(&self) -> &Node {
[INFO] [stdout]    |                             ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 31 |     pub fn right(&self) -> &dyn Node {
[INFO] [stdout]    |                             +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/binop.rs:37:36
[INFO] [stdout]    |
[INFO] [stdout] 37 |     fn accept(&self, visitor: &mut AstVisitor) {
[INFO] [stdout]    |                                    ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 37 |     fn accept(&self, visitor: &mut dyn AstVisitor) {
[INFO] [stdout]    |                                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/unaryop.rs:14:44
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn new(op: UnaryOperator, val: Box<Node>) -> Box<Self> {
[INFO] [stdout]    |                                            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn new(op: UnaryOperator, val: Box<dyn Node>) -> Box<Self> {
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/unaryop.rs:25:27
[INFO] [stdout]    |
[INFO] [stdout] 25 |     pub fn val(&self) -> &Node {
[INFO] [stdout]    |                           ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 25 |     pub fn val(&self) -> &dyn Node {
[INFO] [stdout]    |                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/ast/unaryop.rs:31:36
[INFO] [stdout]    |
[INFO] [stdout] 31 |     fn accept(&self, visitor: &mut AstVisitor) {
[INFO] [stdout]    |                                    ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 31 |     fn accept(&self, visitor: &mut dyn AstVisitor) {
[INFO] [stdout]    |                                    +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/parser.rs:14:58
[INFO] [stdout]    |
[INFO] [stdout] 14 | pub fn evaluate(text: String) -> std::result::Result<Box<Node>, ParseError> {
[INFO] [stdout]    |                                                          ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 14 | pub fn evaluate(text: String) -> std::result::Result<Box<dyn Node>, ParseError> {
[INFO] [stdout]    |                                                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/parser.rs:22:39
[INFO] [stdout]    |
[INFO] [stdout] 22 | fn expr(tokens: Tokens) -> Result<Box<Node>, Tokens> {
[INFO] [stdout]    |                                       ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 22 | fn expr(tokens: Tokens) -> Result<Box<dyn Node>, Tokens> {
[INFO] [stdout]    |                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/parser.rs:36:39
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn term(tokens: Tokens) -> Result<Box<Node>, Tokens> {
[INFO] [stdout]    |                                       ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn term(tokens: Tokens) -> Result<Box<dyn Node>, Tokens> {
[INFO] [stdout]    |                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/parser.rs:50:41
[INFO] [stdout]    |
[INFO] [stdout] 50 | fn parens(tokens: Tokens) -> Result<Box<Node>, Tokens> {
[INFO] [stdout]    |                                         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 50 | fn parens(tokens: Tokens) -> Result<Box<dyn Node>, Tokens> {
[INFO] [stdout]    |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/parser.rs:57:41
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn factor(tokens: Tokens) -> Result<Box<Node>, Tokens> {
[INFO] [stdout]    |                                         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn factor(tokens: Tokens) -> Result<Box<dyn Node>, Tokens> {
[INFO] [stdout]    |                                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/parser.rs:61:42
[INFO] [stdout]    |
[INFO] [stdout] 61 | fn integer(tokens: Tokens) -> Result<Box<Node>, Tokens> {
[INFO] [stdout]    |                                          ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 61 | fn integer(tokens: Tokens) -> Result<Box<dyn Node>, Tokens> {
[INFO] [stdout]    |                                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/parser/parser.rs:68:40
[INFO] [stdout]    |
[INFO] [stdout] 68 | fn unary(tokens: Tokens) -> Result<Box<Node>, Tokens> {
[INFO] [stdout]    |                                        ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 68 | fn unary(tokens: Tokens) -> Result<Box<dyn Node>, Tokens> {
[INFO] [stdout]    |                                        +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/parser/lexer2.rs:44:5
[INFO] [stdout]    |
[INFO] [stdout] 34 |       let mut result: i32 = match chars.first() {
[INFO] [stdout]    |  ___________________________-
[INFO] [stdout] 35 | |         Some(val) => match get_digit(*val) {
[INFO] [stdout] 36 | |             Some(val) if val != => {
[INFO] [stdout] 37 | |                 chars = pop(chars);
[INFO] [stdout] ...  |
[INFO] [stdout] 42 | |         None => return None,
[INFO] [stdout] 43 | |     };
[INFO] [stdout]    | |_____- any code following this `match` expression is unreachable, as all arms diverge
[INFO] [stdout] 44 | /     loop {
[INFO] [stdout] 45 | |         match chars.first() {
[INFO] [stdout] 46 | |             Some(val) => match get_digit(*val) {
[INFO] [stdout] 47 | |                 Some(val) => {
[INFO] [stdout] ...  |
[INFO] [stdout] 54 | |         }
[INFO] [stdout] 55 | |     }
[INFO] [stdout]    | |_____^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors; 22 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `parser` (bin "parser") due to 4 previous errors; 22 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "b5b19fd6f9ca5f024b021ec3b2bcaedf1dfe16bf96d9522e2498ce60e81911dc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b5b19fd6f9ca5f024b021ec3b2bcaedf1dfe16bf96d9522e2498ce60e81911dc", kill_on_drop: false }`
[INFO] [stdout] b5b19fd6f9ca5f024b021ec3b2bcaedf1dfe16bf96d9522e2498ce60e81911dc
