cannot run rust PrimitiveDateTime example - date

Question

I'm trying to solve a very simple rust exercise involving PrimitiveDateTime. I'm trying to run this basic example in my own machine
#![allow(unused)]
extern crate r#time;
fn main() {
use time::{
macros::{date, datetime, time},
PrimitiveDateTime,
};
assert_eq!(
PrimitiveDateTime::new(date!(2019 - 01 - 01), time!(0:00)),
datetime!(2019-01-01 0:00),
);
}
It compile on the rust playground, but it gives me the following errors on my machine:
$ cargo run
Compiling playground v0.1.0 (/home/sas/exercism/rust/playground)
error[E0432]: unresolved imports `time::macros`, `time::PrimitiveDateTime`, `time::macros::date`, `time::macros::datetime`
--> src/main.rs:4:12
|
4 | use time::{PrimitiveDateTime, macros::{date, datetime, time}};
| ^^^^^^^^^^^^^^^^^ ^^^^^^ ^^^^ ^^^^^^^^
| |
| could not find `macros` in `time`
error: cannot find macro `date` in this scope
--> src/main.rs:6:28
|
6 | PrimitiveDateTime::new(date!(2019-01-01), time!(0:00)),
| ^^^^
error: cannot determine resolution for the macro `time`
--> src/main.rs:6:47
|
6 | PrimitiveDateTime::new(date!(2019-01-01), time!(0:00)),
| ^^^^
|
= note: import resolution is stuck, try simplifying macro imports
error: cannot find macro `datetime` in this scope
--> src/main.rs:7:5
|
7 | datetime!(2019-01-01 0:00),
| ^^^^^^^^
error[E0433]: failed to resolve: use of undeclared type `PrimitiveDateTime`
--> src/main.rs:6:5
|
6 | PrimitiveDateTime::new(date!(2019-01-01), time!(0:00)),
| ^^^^^^^^^^^^^^^^^ not found in this scope
|
help: consider importing this struct
|
3 | use time::PrimitiveDateTime;
|
error[E0659]: `time` is ambiguous (name vs any other name during import resolution)
--> src/main.rs:4:5
|
4 | use time::{PrimitiveDateTime, macros::{date, datetime, time}};
| ^^^^ ambiguous name
|
note: `time` could refer to the unresolved item imported here
--> src/main.rs:4:56
|
4 | use time::{PrimitiveDateTime, macros::{date, datetime, time}};
| ^^^^
note: `time` could also refer to the crate imported here
--> src/main.rs:2:1
|
2 | extern crate r#time;
| ^^^^^^^^^^^^^^^^^^^^
= help: use `::time` to refer to this crate unambiguously
= help: or use `crate::time` to refer to this crate unambiguously
Some errors have detailed explanations: E0432, E0433, E0659.
For more information about an error, try `rustc --explain E0432`.
error: could not compile `playground` due to 6 previous errors
This is my Cargo.toml file:
[package]
name = "playground"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
time = "0.3.5"
I'd like to know how to solve it and to understand the error it throws. It seems like some conflict between the time crate and the macro.

Answer 1

Quite a few things in the time crate are feature flag gated, meaning you need to manually specify some feature to enable a certain feature. In your case the macros are missing, taking a look at time's crates.io page shows us you need to add the feature macros to enable this. You can do this by specifying your dependency like so:
[dependencies]
time = { version = "0.3.5", features = ["macros"] }