Rustc does display a correct error message on type missmatch but does not show line numbers

[Yatekii]

I have a case where rustc will show me properly that I have a Type missmatch.
Unfortunately it wont show me where exactly it is.

I tracked the error location down in my own code and can safely say that the code attached is the source, but I couldn't reproduce it yet.
Once I am able to reproduce it, I will report it here, but maybe someone already has a clue or similar experiences.

The faulty error report:

yatekii@partymobile:~/repos/schema_renderer$ cargo build --release
   Compiling schema_parser v0.1.0 (file:///home/yatekii/repos/schema_renderer)
error[E0308]: mismatched types
  |
  = note: expected type `euclid::TypedRect<f32, schema_parser::geometry::SchemaSpace>`
             found type `ncollide2d::bounding_volume::AABB<f32>`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.
error: Could not compile `schema_parser`.

To learn more, run the command again with --verbose.

And the code that triggers it:

// Error triggered by:

let bb = self.model.schema.get_bounding_box();
self.model.view_state.update_from_box_pan(bb);

// Where

pub fn get_bounding_box(&self) -> SchemaAABB {
    use ncollide2d::math::{ Point, Vector };
    let mut aabb = SchemaAABB::new(
        Point::new(0.0, 0.0),
        Point::new(0.0, 0.0)
    );
    for component in &self.drawables {
        let i = &component.instance;
        use schema_parser::helpers::Translatable;
        let bb = &i.get_boundingbox().translated(Vector::new(i.position.x, i.position.y));
        use ncollide2d::bounding_volume::BoundingVolume;
        aabb.merge(bb)
    }
    aabb
}

// and

pub fn update_from_box_pan(&mut self, rect: geometry::SchemaRect) {
    let m = (rect.max_x() - rect.min_x()).max(rect.max_y() - rect.min_y());
    if m > 0.0 {
        self.scale = 2.45 / m;
        self.center = (rect.bottom_left() + rect.top_right().to_vector()) / -2.0;
        self.update_perspective();
        println!("Rect: {}", rect);
    }
}

Rustc version is: nightly-x86_64-unknown-linux-gnu rustc 1.28.0-nightly (86a8f1a 2018-06-17)

[estebank]

Can you verify wether you hit the same output on 1.27?

[Yatekii]

I can try today in the evening, but I wont be successful with a 99% guarantee as I am dependant on multiple nightly-requiring crates, such as relm.

[Yatekii]

Just had the same bug at a different place:

error[E0599]: no method named `to_row_arrays` found for type `nalgebra::base::matrix::Matrix<f32, nalgebra::base::dimension::U4, nalgebra::base::dimension::U4, nalgebra::base::matrix_array::MatrixArray<f32, nalgebra::base::dimension::U4, nalgebra::base::dimension::U4>>` in the current scope

No linenumbers whatsoever. Every other error in the same compilation log displays linenumbers correctly.

[estebank]

That is odd. Could you provide a repo with a repro case? I'd like to see this for myself to try and identify the source of the problem.

[Yatekii]

Sure, I can provide you with the entire repo, the exact commits with the two problems and the excat rustc version when I get home. Could have done this a lot earlier, sorry.

[Yatekii]

Ok, so, the commits are:

• 2nd Faulty Error Output
• 1st Faulty Error Output

The repo should be publicly accessible. Rustc is: rustc 1.28.0-nightly (86a8f1a 2018-06-17). A simple cargo run --release test_data/kicad.lib test_data/kicad.sch should trigger the issue.

I hope this helps.

[Yatekii]

#![feature(proc_macro, wasm_import_module, wasm_custom_section)]

extern crate wasm_bindgen;
use wasm_bindgen::prelude::*;

const MEM_SIZE: usize = 1024 * 1024;
const BLOCK_SIZE: usize = 1024;
const NUM_BLOCKS: usize = MEM_SIZE / BLOCK_SIZE;

struct FAT
{
    memory: [[u8; BLOCK_SIZE]; NUM_BLOCKS]
}

#[wasm_bindgen]
impl FAT
{
    pub fn new() -> FAT
    {
        FAT
        {
            memory: [[0; BLOCK_SIZE], NUM_BLOCKS]
        }
    }
}

#[cfg(test)]
mod tests
{
    use super::*;

    #[test]
    fn test_new_FAT()
    {
        let newFS = FAT::new();
        for blk in 0..NUM_BLOCKS
        {
            for b in 0..BLOCK_SIZE
            {
                assert_eq!(newFS.memory[blk][b], 0);
            }
        }
    }
}

seems to trigger the issue too. Courtesy to @Coolerz on #rust.

The common denominator of this and my code is proc-macro so maybe a look into it is worth it.

[estebank]

That is very likely the culprit, as with proc macros we (usually) lose the spans. I'd have to see if we have any other bit of context that could be used instead.

[Yatekii]

Yeah, I am sorry, I don't understand too much of it yet ;) Thanks for investigating =)

[p4l1ly]

Hi, my temporary hack to get better error information until this problem is solved is described in this gist (see the last paragraph of the README.md): https://gist.github.com/p4l1ly/6dbcb40fb3bbb450598876b068762939

[iddm]

Still happens for as well, on the latest nightly (1.39).

[iddm]

Issue in docker image: rust-lang/docker-rust-nightly#17

UPD: it has nothing to do with docker, it is a problem of rustc.

[iddm]

Is anybody working on this problem? Because I can't work on my project. Both nightly docker images I use don't show lines, only errors, it is really very hard to guess what is causing errors and where.