[INFO] cloning repository https://github.com/rust-kotlin/rust_projects [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/rust-kotlin/rust_projects" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frust-kotlin%2Frust_projects", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frust-kotlin%2Frust_projects'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] d0a794ba59af115d7be1e19040c7aaeb5a13715c [INFO] testing rust-kotlin/rust_projects against beta-2025-10-28 for beta-1.92-2 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frust-kotlin%2Frust_projects" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'... [INFO] [stderr] done. [INFO] started tweaking git repo https://github.com/rust-kotlin/rust_projects [INFO] finished tweaking git repo https://github.com/rust-kotlin/rust_projects [INFO] tweaked toml for git repo https://github.com/rust-kotlin/rust_projects written to /workspace/builds/worker-0-tc2/source/Cargo.toml [INFO] validating manifest of git repo https://github.com/rust-kotlin/rust_projects on toolchain beta-2025-10-28 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-10-28" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate git repo https://github.com/rust-kotlin/rust_projects 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-2025-10-28" "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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-10-28" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] cfa30d6e3d39d0a7830b5d39be8c8089f88b5752222a5ae8bfeee982e6c23869 [INFO] running `Command { std: "docker" "start" "-a" "cfa30d6e3d39d0a7830b5d39be8c8089f88b5752222a5ae8bfeee982e6c23869", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "cfa30d6e3d39d0a7830b5d39be8c8089f88b5752222a5ae8bfeee982e6c23869", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "cfa30d6e3d39d0a7830b5d39be8c8089f88b5752222a5ae8bfeee982e6c23869", kill_on_drop: false }` [INFO] [stdout] cfa30d6e3d39d0a7830b5d39be8c8089f88b5752222a5ae8bfeee982e6c23869 [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=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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-10-28" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] ae1e56ba57c4cdb9d253592d3e04feb8e56b60d679f87572a31be146f34379cb [INFO] running `Command { std: "docker" "start" "-a" "ae1e56ba57c4cdb9d253592d3e04feb8e56b60d679f87572a31be146f34379cb", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.137 [INFO] [stderr] Compiling atty v0.2.14 [INFO] [stderr] Compiling colored v2.0.0 [INFO] [stderr] Compiling rust_projects v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: variable `my_number` is assigned to, but never used [INFO] [stdout] --> src/bin/12debug-macro.rs:3:9 [INFO] [stdout] | [INFO] [stdout] 3 | let mut my_number = dbg!(9); [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: consider using `_my_number` instead [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `double_vec` [INFO] [stdout] --> src/bin/12debug-macro.rs:14:9 [INFO] [stdout] | [INFO] [stdout] 14 | let double_vec = new_vec [INFO] [stdout] | ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_double_vec` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: value assigned to `my_number` is never read [INFO] [stdout] --> src/bin/12debug-macro.rs:4:10 [INFO] [stdout] | [INFO] [stdout] 4 | dbg!(my_number += 10); [INFO] [stdout] | ^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = help: maybe it is overwritten before being read? [INFO] [stdout] = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `book` [INFO] [stdout] --> src/bin/17todo-macro.rs:10:13 [INFO] [stdout] | [INFO] [stdout] 10 | fn get_book(book: &Book) -> Option { [INFO] [stdout] | ^^^^ help: if this is intentional, prefix it with an underscore: `_book` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `book` [INFO] [stdout] --> src/bin/17todo-macro.rs:14:16 [INFO] [stdout] | [INFO] [stdout] 14 | fn delete_book(book: Book) -> Result<(), String> { [INFO] [stdout] | ^^^^ help: if this is intentional, prefix it with an underscore: `_book` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: struct `Book` is never constructed [INFO] [stdout] --> src/bin/17todo-macro.rs:1:8 [INFO] [stdout] | [INFO] [stdout] 1 | struct Book {} // Okay, first I need a book struct. [INFO] [stdout] | ^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `SoftCover` is never constructed [INFO] [stdout] --> src/bin/17todo-macro.rs:7:5 [INFO] [stdout] | [INFO] [stdout] 4 | enum BookType { [INFO] [stdout] | -------- variant in this enum [INFO] [stdout] ... [INFO] [stdout] 7 | SoftCover, [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: function `get_book` is never used [INFO] [stdout] --> src/bin/17todo-macro.rs:10:4 [INFO] [stdout] | [INFO] [stdout] 10 | fn get_book(book: &Book) -> Option { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: function `delete_book` is never used [INFO] [stdout] --> src/bin/17todo-macro.rs:14:4 [INFO] [stdout] | [INFO] [stdout] 14 | fn delete_book(book: Book) -> Result<(), String> { [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/bin/14interior-mutability.rs:67:9 [INFO] [stdout] | [INFO] [stdout] 67 | let mut mutex_changer = my_mutex.lock().unwrap(); [INFO] [stdout] | ----^^^^^^^^^^^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/bin/14interior-mutability.rs:68:9 [INFO] [stdout] | [INFO] [stdout] 68 | let mut other_mutex_changer = my_mutex.try_lock(); // try to get the lock [INFO] [stdout] | ----^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `mutex_changer` [INFO] [stdout] --> src/bin/14interior-mutability.rs:67:9 [INFO] [stdout] | [INFO] [stdout] 67 | let mut mutex_changer = my_mutex.lock().unwrap(); [INFO] [stdout] | ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_mutex_changer` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: fields `company_name`, `model_name`, `screen_size`, `memory`, and `date_issued` are never read [INFO] [stdout] --> src/bin/14interior-mutability.rs:8:5 [INFO] [stdout] | [INFO] [stdout] 7 | struct PhoneModel { [INFO] [stdout] | ---------- fields in this struct [INFO] [stdout] 8 | company_name: String, [INFO] [stdout] | ^^^^^^^^^^^^ [INFO] [stdout] 9 | model_name: String, [INFO] [stdout] | ^^^^^^^^^^ [INFO] [stdout] 10 | screen_size: f32, [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] 11 | memory: usize, [INFO] [stdout] | ^^^^^^ [INFO] [stdout] 12 | date_issued: u32, [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: fields `id`, `year_registered`, and `username` are never read [INFO] [stdout] --> src/bin/14interior-mutability.rs:17:5 [INFO] [stdout] | [INFO] [stdout] 16 | struct User { [INFO] [stdout] | ---- fields in this struct [INFO] [stdout] 17 | id: u32, [INFO] [stdout] | ^^ [INFO] [stdout] 18 | year_registered: u32, [INFO] [stdout] | ^^^^^^^^^^^^^^^ [INFO] [stdout] 19 | username: String, [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `User` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `canada_cities` [INFO] [stdout] --> src/bin/18reference-counter.rs:24:9 [INFO] [stdout] | [INFO] [stdout] 24 | let canada_cities = CityData { [INFO] [stdout] | ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_canada_cities` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `new_owner` [INFO] [stdout] --> src/bin/18reference-counter.rs:30:9 [INFO] [stdout] | [INFO] [stdout] 30 | let new_owner = calgary.city_history.clone(); [INFO] [stdout] | ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_owner` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: field `population` is never read [INFO] [stdout] --> src/bin/18reference-counter.rs:6:5 [INFO] [stdout] | [INFO] [stdout] 4 | struct City { [INFO] [stdout] | ---- field in this struct [INFO] [stdout] 5 | name: String, [INFO] [stdout] 6 | population: u32, [INFO] [stdout] | ^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `City` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: fields `names` and `histories` are never read [INFO] [stdout] --> src/bin/18reference-counter.rs:12:5 [INFO] [stdout] | [INFO] [stdout] 11 | struct CityData { [INFO] [stdout] | -------- fields in this struct [INFO] [stdout] 12 | names: Vec, [INFO] [stdout] | ^^^^^ [INFO] [stdout] 13 | histories: Vec>, // A Vec of Strings inside Rcs [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `CityData` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: fields `0` and `1` are never read [INFO] [stdout] --> src/bin/20smart-pointer.rs:54:10 [INFO] [stdout] | [INFO] [stdout] 54 | Cons(i32, Box), [INFO] [stdout] | ---- ^^^ ^^^^^^^^^ [INFO] [stdout] | | [INFO] [stdout] | fields in this variant [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields [INFO] [stdout] | [INFO] [stdout] 54 - Cons(i32, Box), [INFO] [stdout] 54 + Cons((), ()), [INFO] [stdout] | [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: function `forever` is never used [INFO] [stdout] --> src/bin/23generics.rs:31:4 [INFO] [stdout] | [INFO] [stdout] 31 | fn forever() -> ! { [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `fourth` [INFO] [stdout] --> src/bin/07question-operator.rs:32:9 [INFO] [stdout] | [INFO] [stdout] 32 | let fourth = get_fourth(&my_vec); [INFO] [stdout] | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_fourth` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused label [INFO] [stdout] --> src/bin/04loop.rs:30:13 [INFO] [stdout] | [INFO] [stdout] 30 | 'second_loop: loop { [INFO] [stdout] | ^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_labels)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `array` [INFO] [stdout] --> src/bin/03struct-and-enum.rs:61:9 [INFO] [stdout] | [INFO] [stdout] 61 | let array = [String::from("666"), String::from("999")]; [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_array` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: struct `FileDirectory` is never constructed [INFO] [stdout] --> src/bin/03struct-and-enum.rs:2:8 [INFO] [stdout] | [INFO] [stdout] 2 | struct FileDirectory; [INFO] [stdout] | ^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: struct `Color` is never constructed [INFO] [stdout] --> src/bin/03struct-and-enum.rs:5:8 [INFO] [stdout] | [INFO] [stdout] 5 | struct Color(u8, u8, u8); [INFO] [stdout] | ^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: struct `SizeAndColor` is never constructed [INFO] [stdout] --> src/bin/03struct-and-enum.rs:8:8 [INFO] [stdout] | [INFO] [stdout] 8 | struct SizeAndColor { [INFO] [stdout] | ^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused imports: `Cell` and `RefCell` [INFO] [stdout] --> src/bin/16type-aliases.rs:1:17 [INFO] [stdout] | [INFO] [stdout] 1 | use std::cell::{Cell, RefCell}; [INFO] [stdout] | ^^^^ ^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: type alias `CharacterVec` is never used [INFO] [stdout] --> src/bin/16type-aliases.rs:2:6 [INFO] [stdout] | [INFO] [stdout] 2 | type CharacterVec = Vec; [INFO] [stdout] | ^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: type alias `SkipFourTakeFive` is never used [INFO] [stdout] --> src/bin/16type-aliases.rs:3:6 [INFO] [stdout] | [INFO] [stdout] 3 | type SkipFourTakeFive<'a> = std::iter::Take>>; [INFO] [stdout] | ^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: function `returns` is never used [INFO] [stdout] --> src/bin/16type-aliases.rs:5:4 [INFO] [stdout] | [INFO] [stdout] 5 | fn returns<'a>(input: &'a CharacterVec) -> SkipFourTakeFive { [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: hiding a lifetime that's named elsewhere is confusing [INFO] [stdout] --> src/bin/16type-aliases.rs:5:44 [INFO] [stdout] | [INFO] [stdout] 5 | fn returns<'a>(input: &'a CharacterVec) -> SkipFourTakeFive { [INFO] [stdout] | -- ^^^^^^^^^^^^^^^^ the same lifetime is hidden here [INFO] [stdout] | | [INFO] [stdout] | the lifetime is named here [INFO] [stdout] | [INFO] [stdout] = help: the same lifetime is referred to in inconsistent ways, making the signature confusing [INFO] [stdout] = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default [INFO] [stdout] help: consistently use `'a` [INFO] [stdout] | [INFO] [stdout] 5 | fn returns<'a>(input: &'a CharacterVec) -> SkipFourTakeFive<'a> { [INFO] [stdout] | ++++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused import: `std::path::Components` [INFO] [stdout] --> src/bin/28trait-object.rs:1:5 [INFO] [stdout] | [INFO] [stdout] 1 | use std::path::Components; [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0499]: cannot borrow `*map` as mutable more than once at a time [INFO] [stdout] --> src/main.rs:15:17 [INFO] [stdout] | [INFO] [stdout] 7 | fn get_default<'m, K, V>(map: &'m mut HashMap, key: K) -> &'m mut V [INFO] [stdout] | -- lifetime `'m` defined here [INFO] [stdout] ... [INFO] [stdout] 12 | match map.get_mut(&key) { [INFO] [stdout] | - --- first mutable borrow occurs here [INFO] [stdout] | _________| [INFO] [stdout] | | [INFO] [stdout] 13 | | Some(value) => value, [INFO] [stdout] 14 | | None => { [INFO] [stdout] 15 | | map.insert(key.clone(), V::default()); [INFO] [stdout] | | ^^^ second mutable borrow occurs here [INFO] [stdout] ... | [INFO] [stdout] 18 | | } [INFO] [stdout] | |_________- returning this value requires that `*map` is borrowed for `'m` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0499]: cannot borrow `*map` as mutable more than once at a time [INFO] [stdout] --> src/main.rs:16:17 [INFO] [stdout] | [INFO] [stdout] 7 | fn get_default<'m, K, V>(map: &'m mut HashMap, key: K) -> &'m mut V [INFO] [stdout] | -- lifetime `'m` defined here [INFO] [stdout] ... [INFO] [stdout] 12 | match map.get_mut(&key) { [INFO] [stdout] | - --- first mutable borrow occurs here [INFO] [stdout] | _________| [INFO] [stdout] | | [INFO] [stdout] 13 | | Some(value) => value, [INFO] [stdout] 14 | | None => { [INFO] [stdout] 15 | | map.insert(key.clone(), V::default()); [INFO] [stdout] 16 | | map.get_mut(&key).unwrap() [INFO] [stdout] | | ^^^ second mutable borrow occurs here [INFO] [stdout] 17 | | } [INFO] [stdout] 18 | | } [INFO] [stdout] | |_________- returning this value requires that `*map` is borrowed for `'m` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] For more information about this error, try `rustc --explain E0499`. [INFO] [stdout] [INFO] [stderr] error: could not compile `rust_projects` (bin "rust_projects") due to 2 previous errors [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] running `Command { std: "docker" "inspect" "ae1e56ba57c4cdb9d253592d3e04feb8e56b60d679f87572a31be146f34379cb", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "ae1e56ba57c4cdb9d253592d3e04feb8e56b60d679f87572a31be146f34379cb", kill_on_drop: false }` [INFO] [stdout] ae1e56ba57c4cdb9d253592d3e04feb8e56b60d679f87572a31be146f34379cb