Resolving imports in Rust

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I'm having trouble with importing rand crate from crates.io. After adding the line rand="0.8.3" and then running command cargo build for the project, it keeps displaying the same errors:

error[E0432]: unresolved import `rand`
 --> main.rs:1:5
  |
1 | use rand::Rng;
  |     ^^^^ maybe a missing crate `rand`?

error[E0433]: failed to resolve: use of undeclared crate or module `rand`
 --> main.rs:4:25
  |
4 |     let secret_number = rand::thread_rng().gen_range(1..=11);
  |                         ^^^^ use of undeclared crate or module `rand`

error: aborting due to 2 previous errors

the cargo.toml file

[package]
name = "roller"
version = "0.1.0"
authors = ["User"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
rand = "0.8.3"

Basically the simplest reproducible example is this single line of code:

 use rand::Rng;

 fn main(){
    let secret_number = rand::thread_rng().gen_range(1..=11);
    print!("{}",secret_number);
 }

What's wrong with it?


Just in case:
The **cargo.lock**file:
# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
[[package]]
name = "cfg-if"
version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"

[[package]]
name = "getrandom"
version = "0.2.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c9495705279e7140bf035dde1f6e750c162df8b625267cd52cc44e0b156732c8"
dependencies = [
 "cfg-if",
 "libc",
 "wasi",
]

[[package]]
name = "libc"
version = "0.2.86"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b7282d924be3275cec7f6756ff4121987bc6481325397dde6ba3e7802b1a8b1c"

[[package]]
name = "ppv-lite86"
version = "0.2.10"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"

[[package]]
name = "rand"
version = "0.8.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "0ef9e7e66b4468674bfcb0c81af8b7fa0bb154fa9f28eb840da5c447baeb8d7e"
dependencies = [
 "libc",
 "rand_chacha",
 "rand_core",
 "rand_hc",
]

[[package]]
name = "rand_chacha"
version = "0.3.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e12735cf05c9e10bf21534da50a147b924d555dc7a547c42e6bb2d5b6017ae0d"
dependencies = [
 "ppv-lite86",
 "rand_core",
]

[[package]]
name = "rand_core"
version = "0.6.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "34cf66eb183df1c5876e2dcf6b13d57340741e8dc255b48e40a26de954d06ae7"
dependencies = [
 "getrandom",
]

[[package]]
name = "rand_hc"
version = "0.3.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "3190ef7066a446f2e7f42e239d161e905420ccab01eb967c9eb27d21b2322a73"
dependencies = [
 "rand_core",
]

[[package]]
name = "roller"
version = "0.1.0"
dependencies = [
 "rand",
]

[[package]]
name = "wasi"
version = "0.10.2+wasi-snapshot-preview1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
3 Answers

got the same error when I run it with vs code(rust-analyzer).

When you press the run button rustic main.rs this command is called in terminal, it will cause error.

Type this in terminal,

cargo build
cargo run

It works well

If you think that you did everything right and get a strange unable to import error like this then you could try cargo clean.

That will allow you to fully re-build your binary/library after that.

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