Error for extern crate

[xuzhao9]

For example following code snippet:

extern crate regex;   // on this line flycheck has error 'can't find crate for 'regex''
fn main() {
}

Actually I have already setup regex crate in Cargo.toml, dependencies section.
Is there a way to prevent flycheck-rust stop checking extern crate related lines?

[swsnr]

@NUK9 Did you run cargo build? Does the library exist in target/debug/deps/?

[mkpankov]

Last time I stumbled upon this, this was especially a ptoblem with crates, that are bundled with rustc. For example, using term from crates.io would emit "can't find crate; multiple candidates" error on extern crate term.

This was due to direct launch of rustc, as opposed to cargo running rustc, which supplies additional options to define proper dependencies paths.

Also, AFAIK, cargo rustc command was implemented - does flycheck-rust use it now or not yet?

[swsnr]

@mkpankov Uhm, we obviously have a different error here… I appreciate your input, but please let us focus on solving this specific issue to help @NUK9 instead of discussing the general approach of how we check Rust code in Flycheck. Thanks you.

See #8 for ideas on how to use Cargo instead.

[xuzhao9]

I found out the reason: I need to run flycheck-rust-setup. Running that function solved this problem.

[swsnr]

@NUK9 Uhm, that's actually part of the installation instructions. Were these instructions somehow unclear to you?

[xuzhao9]

@lunaryorn Sorry I didn't visit github page, just installed the package from MELPA and I'm new to flycheck. Seems this init style also applies to other flycheck modes (e.g. flycheck-haskell) so I suggest it is my problem.

[swsnr]

@NUK9 Please try to read the documentation of new packages in future.

[tomjakubowski]

@NUK9 just in case you don't know, from M-x package-list-packages, you can select a package and hit ? to see information about it. Many packages include a brief README-like description, and all MELPA packages at least should have an HTTP link to a package homepage where there's often usage documentation.

You can also see this information for an installed package with C-h P (capitalized P).

[xuzhao9]

@tomjakubowski Thank you! I will carefully read the documentation before firing an issue on github next time.

[swsnr]

@NUK9 I've improved the commentary of Flycheck and Flycheck Rust a bit to make things more clear, hopefully.