MRE for https://stackoverflow.com/questions/56901973/errore0599-no-method-named-gen-found-for-type-mut-g-in-the-current-scope

Cargo.toml

[package]
name = "ex1"
version = "0.1.0"
authors = ["Russell Brown <russell.brown@joyent.com>"]
edition = "2018"

[dependencies]

[dev-dependencies]
quickcheck = "0.8.5"
rand = "0.7.0"

main.rs

#[derive(Debug, PartialEq, Clone)]
struct Point {
    x: u32,
    y: u32,
}

fn main() {
    let p = Point { x: 12, y: 13 };
    println!("point is {:?}", p);
}

#[cfg(test)]
mod tests {
    use super::*;
    use quickcheck::{quickcheck, Arbitrary, Gen};
    use rand::Rng;

    impl Arbitrary for Point {
        fn arbitrary<G: Gen>(g: &mut G) -> Point {
            let x = g.gen::<u32>();
            let y = g.gen::<u32>();

            Point { x, y }
        }
    }

    quickcheck! {
        fn prop(p: Point) -> bool {
            p == p
        }
    }
}

verbose out

12:38:48:ex1(mre *) $ cargo test --verbose
       Fresh spin v0.5.0
       Fresh autocfg v0.1.4
       Fresh rand_core v0.4.0
       Fresh ucd-util v0.1.3
       Fresh utf8-ranges v1.0.3
       Fresh ppv-lite86 v0.2.5
       Fresh cfg-if v0.1.9
       Fresh lazy_static v1.3.0
       Fresh regex-syntax v0.6.7
       Fresh rand_core v0.3.1
       Fresh rand_jitter v0.1.4
       Fresh log v0.4.6
       Fresh memchr v2.2.0
       Fresh libc v0.2.58
       Fresh thread_local v0.3.6
       Fresh c2-chacha v0.2.2
       Fresh aho-corasick v0.7.4
       Fresh getrandom v0.1.6
       Fresh rand_hc v0.1.0
       Fresh rand_os v0.1.3
       Fresh rand_chacha v0.1.1
       Fresh rand_xorshift v0.1.1
       Fresh rand_pcg v0.1.2
       Fresh rand_isaac v0.1.1
       Fresh regex v1.1.8
       Fresh rand_core v0.5.0
       Fresh env_logger v0.6.2
       Fresh rand_chacha v0.2.0
       Fresh rand v0.6.5
       Fresh rand v0.7.0
       Fresh quickcheck v0.8.5
   Compiling ex1 v0.1.0 (/home/russell/dev/rust/talent-plan-1/bb2/ex1)
     Running `rustc --edition=2018 --crate-name ex1 src/main.rs --color always --emit=dep-info,link -C debuginfo=2 --test -C metadata=a7f0c5284470e309 -C extra-filename=-a7f0c5284470e309 --out-dir /home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps -C incremental=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/incremental -L dependency=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps --extern quickcheck=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps/libquickcheck-714f2be38d602717.rlib --extern rand=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps/librand-261f8b5c0796a35b.rlib`
error[E0599]: no method named `gen` found for type `&mut G` in the current scope
  --> src/main.rs:20:23
   |
20 |             let x = g.gen::<u32>();
   |                       ^^^
   |
   = note: the method `gen` exists but the following trait bounds were not satisfied:
           `&mut G : rand::Rng`
           `G : rand::Rng`
   = help: items from traits can only be used if the trait is in scope
   = note: the following trait is implemented but not in scope, perhaps add a `use` for it:
           `use rand::Rng;`

error[E0599]: no method named `gen` found for type `&mut G` in the current scope
  --> src/main.rs:21:23
   |
21 |             let y = g.gen::<u32>();
   |                       ^^^
   |
   = note: the method `gen` exists but the following trait bounds were not satisfied:
           `&mut G : rand::Rng`
           `G : rand::Rng`
   = help: items from traits can only be used if the trait is in scope
   = note: the following trait is implemented but not in scope, perhaps add a `use` for it:
           `use rand::Rng;`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0599`.
error: Could not compile `ex1`.

Caused by:
  process didn't exit successfully: `rustc --edition=2018 --crate-name ex1 src/main.rs --color always --emit=dep-info,link -C debuginfo=2 --test -C metadata=a7f0c5284470e309 -C extra-filename=-a7f0c5284470e309 --out-dir /home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps -C incremental=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/incremental -L dependency=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps --extern quickcheck=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps/libquickcheck-714f2be38d602717.rlib --extern rand=/home/russell/dev/rust/talent-plan-1/bb2/ex1/target/debug/deps/librand-261f8b5c0796a35b.rlib` (exit code: 1)