Rust 1.18 regression: coinbaser 0.1.0

[alexcrichton]

Reported on cargobomb

boom! running `docker start -a fcd992283fd7ae3f00c77dc9c371733b58ef79cf654f4113f69b8555e73a9612`
kablam!    Compiling coinbaser v0.1.0 (file:///source)
kablam! error[E0432]: unresolved import `hyper::client::Client`
kablam!  --> src/coinbaser.rs:5:5
kablam!   |
kablam! 5 | use hyper::client::Client;
kablam!   |     ^^^^^^^^^^^^^^^^^^^^^ Maybe a missing `extern crate hyper;`?
kablam! 
kablam! error[E0432]: unresolved import `hyper::status::StatusCode`
kablam!  --> src/coinbaser.rs:6:5
kablam!   |
kablam! 6 | use hyper::status::StatusCode;
kablam!   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ Maybe a missing `extern crate hyper;`?
kablam! 
kablam! error[E0432]: unresolved import `hyper::Url`
kablam!  --> src/coinbaser.rs:7:5
kablam!   |
kablam! 7 | use hyper::Url;
kablam!   |     ^^^^^^^^^^ Maybe a missing `extern crate hyper;`?
kablam! 
kablam! error[E0432]: unresolved import `error::Error`
kablam!  --> src/coinbaser.rs:9:5
kablam!   |
kablam! 9 | use error::Error as _CoinError;
kablam!   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ Did you mean `std::error`?
kablam! 
kablam! error: main function not found
kablam! 
kablam! error: aborting due to 5 previous errors
kablam! 
kablam! error: Could not compile `coinbaser`.
kablam! 

Unfortunately the source is not available, but @patrickjm can you perhaps help reproduce?

[jethrogb]

What do you mean source is not available? How did you find the regression in the first place?

[brson]

@jethrogb I mean that I can't find the git repo. The source can be acquired from the published crate tarball.

Edit: er, I didn't file this bug, but that's what @alexcrichton meant.

[patrickjm]

The repo has been deleted for some time now - I tried to delete it from cargo but that's not allowed.

[brson]

Should probably still be investigated, unless @patrickjm doesn't want us testing his yanked crate. We'll have to grab it from crates.io.

I wonder if maybe cargobomb shouldn't test yanked crates.

[alexcrichton]

This is a regression in Cargo. With a Cargo.toml that looks like:

[project]
name = "foo"

[[bin]]
name = "foo"

And files at src/main.rs and src/foo.rs on stable Cargo will compile src/main.rs, on beta Cargo will compile src/foo.rs instead.

cc @jmatraszek, is this related to rust-lang/cargo#3609 perhaps?

[jmatraszek]

Hi @alexcrichton, will investigate this today, but looks like it is related.

[alexcrichton]

Thanks @jmatraszek!

[patrickjm]

Sorry about the hassle guys. I removed it because I didn't want my useless and dead project polluting things up, but that just caused more trouble!

No worries about testing my yanked crate. @brson

[alexcrichton]

@patrickjm oh no worries! This crate helped us detect a regression and what's what we're worried about :)

[jmatraszek]

Hi @alexcrichton,
I think this was caused by this: /~https://github.com/rust-lang/cargo/blob/master/src/cargo/util/toml.rs#L1367, but it worked because of the bug I fixed in 3609 (cargo always assumed src/main.rs as a source file for a bin target).

You can find the proposed fix in rust-lang/cargo#3898. I tried to get rid of quick fixes and implement a full featured solution for inferring bin target's source file paths. Please review the inferring logic — I am not 100% sure that it covers all cargo's usecases, but it seems reasonable for me.