[INFO] cloning repository https://github.com/playXE/libextra
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/playXE/libextra" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FplayXE%2Flibextra", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FplayXE%2Flibextra'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cfc89fff0d457a4fd7b846a4a01d54eb5dca5de6
[INFO] checking playXE/libextra against master#9e293ae9f8abecb0be5105787d181518c9012a19 for pr-146440-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FplayXE%2Flibextra" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/playXE/libextra
[INFO] finished tweaking git repo https://github.com/playXE/libextra
[INFO] tweaked toml for git repo https://github.com/playXE/libextra written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/playXE/libextra on toolchain 9e293ae9f8abecb0be5105787d181518c9012a19
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+9e293ae9f8abecb0be5105787d181518c9012a19" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/playXE/libextra 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" "+9e293ae9f8abecb0be5105787d181518c9012a19" "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-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+9e293ae9f8abecb0be5105787d181518c9012a19" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7b35f38c89647af8c27aba145ef8fbd889cbb2724878867575f7b6dc8109d94a
[INFO] running `Command { std: "docker" "start" "-a" "7b35f38c89647af8c27aba145ef8fbd889cbb2724878867575f7b6dc8109d94a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7b35f38c89647af8c27aba145ef8fbd889cbb2724878867575f7b6dc8109d94a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b35f38c89647af8c27aba145ef8fbd889cbb2724878867575f7b6dc8109d94a", kill_on_drop: false }`
[INFO] [stdout] 7b35f38c89647af8c27aba145ef8fbd889cbb2724878867575f7b6dc8109d94a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+9e293ae9f8abecb0be5105787d181518c9012a19" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b151faf0986550ef22ea376d7afa2e2c9bfcc042e6d23d24457dcbcc830d1627
[INFO] running `Command { std: "docker" "start" "-a" "b151faf0986550ef22ea376d7afa2e2c9bfcc042e6d23d24457dcbcc830d1627", kill_on_drop: false }`
[INFO] [stderr]     Checking libextra v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `Enumerate` and `FilterMap`
[INFO] [stdout]  --> src/map.rs:3:17
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::iter::{Enumerate, FilterMap};
[INFO] [stdout]   |                 ^^^^^^^^^  ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused macro definition: `iterator`
[INFO] [stdout]   --> src/map.rs:36:14
[INFO] [stdout]    |
[INFO] [stdout] 36 | macro_rules! iterator {
[INFO] [stdout]    |              ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_macros)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/bitv.rs:5:47
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn iterate_bits(base: usize, bits: usize, f: &Fn(usize) -> bool) -> bool {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn iterate_bits(base: usize, bits: usize, f: &dyn Fn(usize) -> bool) -> bool {
[INFO] [stdout]   |                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/map.rs:33:11
[INFO] [stdout]    |
[INFO] [stdout] 33 |     iter: Iterator<Item = Option<T>> + 'a,
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 33 |     iter: dyn Iterator<Item = Option<T>> + 'a,
[INFO] [stdout]    |           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/vec.rs:5:25
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn count(&self, f: &Fn(&T) -> bool) -> usize;
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn count(&self, f: &dyn Fn(&T) -> bool) -> usize;
[INFO] [stdout]   |                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/vec.rs:16:25
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn count(&self, f: &Fn(&T) -> bool) -> usize {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn count(&self, f: &dyn Fn(&T) -> bool) -> usize {
[INFO] [stdout]    |                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bitv.rs:40:63
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn process(&mut self, b: &BigBitv, nbits: usize, op: &Fn(usize, usize) -> usize) -> bool {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn process(&mut self, b: &BigBitv, nbits: usize, op: &dyn Fn(usize, usize) -> usize) -> bool {
[INFO] [stdout]    |                                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/bitv.rs:219:53
[INFO] [stdout]     |
[INFO] [stdout] 219 |     pub fn other_op(&mut self, other: &BitvSet, f: &Fn(usize, usize) -> usize) {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 219 |     pub fn other_op(&mut self, other: &BitvSet, f: &dyn Fn(usize, usize) -> usize) {
[INFO] [stdout]     |                                                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `other`
[INFO] [stdout]    --> src/bitv.rs:182:30
[INFO] [stdout]     |
[INFO] [stdout] 182 |     pub fn difference(&self, other: &BitvSet, f: &fn(&usize) -> bool) -> bool {
[INFO] [stdout]     |                              ^^^^^ help: if this is intentional, prefix it with an underscore: `_other`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]    --> src/bitv.rs:182:47
[INFO] [stdout]     |
[INFO] [stdout] 182 |     pub fn difference(&self, other: &BitvSet, f: &fn(&usize) -> bool) -> bool {
[INFO] [stdout]     |                                               ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `iterate_bits` is never used
[INFO] [stdout]  --> src/bitv.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn iterate_bits(base: usize, bits: usize, f: &Fn(usize) -> bool) -> bool {
[INFO] [stdout]   |    ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Op` is never used
[INFO] [stdout]    --> src/bitv.rs:117:6
[INFO] [stdout]     |
[INFO] [stdout] 117 | enum Op {
[INFO] [stdout]     |      ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's named elsewhere is confusing
[INFO] [stdout]    --> src/bitv.rs:207:34
[INFO] [stdout]     |
[INFO] [stdout] 207 |     pub fn iter<'a>(&'a self) -> BitvSetIterator {
[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] 207 |     pub fn iter<'a>(&'a self) -> BitvSetIterator<'a> {
[INFO] [stdout]     |                                                 ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Enumerate` and `FilterMap`
[INFO] [stdout]  --> src/map.rs:3:17
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::iter::{Enumerate, FilterMap};
[INFO] [stdout]   |                 ^^^^^^^^^  ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused macro definition: `iterator`
[INFO] [stdout]   --> src/map.rs:36:14
[INFO] [stdout]    |
[INFO] [stdout] 36 | macro_rules! iterator {
[INFO] [stdout]    |              ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_macros)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/bitv.rs:5:47
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn iterate_bits(base: usize, bits: usize, f: &Fn(usize) -> bool) -> bool {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn iterate_bits(base: usize, bits: usize, f: &dyn Fn(usize) -> bool) -> bool {
[INFO] [stdout]   |                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/map.rs:33:11
[INFO] [stdout]    |
[INFO] [stdout] 33 |     iter: Iterator<Item = Option<T>> + 'a,
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 33 |     iter: dyn Iterator<Item = Option<T>> + 'a,
[INFO] [stdout]    |           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/vec.rs:5:25
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn count(&self, f: &Fn(&T) -> bool) -> usize;
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn count(&self, f: &dyn Fn(&T) -> bool) -> usize;
[INFO] [stdout]   |                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/vec.rs:16:25
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn count(&self, f: &Fn(&T) -> bool) -> usize {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fn count(&self, f: &dyn Fn(&T) -> bool) -> usize {
[INFO] [stdout]    |                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bitv.rs:40:63
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn process(&mut self, b: &BigBitv, nbits: usize, op: &Fn(usize, usize) -> usize) -> bool {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 40 |     pub fn process(&mut self, b: &BigBitv, nbits: usize, op: &dyn Fn(usize, usize) -> usize) -> bool {
[INFO] [stdout]    |                                                               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/bitv.rs:219:53
[INFO] [stdout]     |
[INFO] [stdout] 219 |     pub fn other_op(&mut self, other: &BitvSet, f: &Fn(usize, usize) -> usize) {
[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/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 219 |     pub fn other_op(&mut self, other: &BitvSet, f: &dyn Fn(usize, usize) -> usize) {
[INFO] [stdout]     |                                                     +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `other`
[INFO] [stdout]    --> src/bitv.rs:182:30
[INFO] [stdout]     |
[INFO] [stdout] 182 |     pub fn difference(&self, other: &BitvSet, f: &fn(&usize) -> bool) -> bool {
[INFO] [stdout]     |                              ^^^^^ help: if this is intentional, prefix it with an underscore: `_other`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]    --> src/bitv.rs:182:47
[INFO] [stdout]     |
[INFO] [stdout] 182 |     pub fn difference(&self, other: &BitvSet, f: &fn(&usize) -> bool) -> bool {
[INFO] [stdout]     |                                               ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `iterate_bits` is never used
[INFO] [stdout]  --> src/bitv.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn iterate_bits(base: usize, bits: usize, f: &Fn(usize) -> bool) -> bool {
[INFO] [stdout]   |    ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Op` is never used
[INFO] [stdout]    --> src/bitv.rs:117:6
[INFO] [stdout]     |
[INFO] [stdout] 117 | enum Op {
[INFO] [stdout]     |      ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's named elsewhere is confusing
[INFO] [stdout]    --> src/bitv.rs:207:34
[INFO] [stdout]     |
[INFO] [stdout] 207 |     pub fn iter<'a>(&'a self) -> BitvSetIterator {
[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] 207 |     pub fn iter<'a>(&'a self) -> BitvSetIterator<'a> {
[INFO] [stdout]     |                                                 ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `Command { std: "docker" "inspect" "b151faf0986550ef22ea376d7afa2e2c9bfcc042e6d23d24457dcbcc830d1627", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b151faf0986550ef22ea376d7afa2e2c9bfcc042e6d23d24457dcbcc830d1627", kill_on_drop: false }`
[INFO] [stdout] b151faf0986550ef22ea376d7afa2e2c9bfcc042e6d23d24457dcbcc830d1627