rust-skeptic: multiple matching crates when deps are duplicated

I get a weird error when I use the combination of:

rust-skeptic
cargo check
cargo test
on a proc_macro crate

This looks like a skeptic (or cargo check) bug and it is dependent on the order of cargo check and cargo test.

error[E0464]: multiple matching crates for `cargo_check_bug`
 --> /tmp/rust-skeptic.U89a9gBDNE36/test.rs:1:1
  |
1 | extern crate cargo_check_bug;
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: candidates:
  = note: path: /home/colin/projects/rust/cargo_check_bug/target/debug/deps/libcargo_check_bug-0b76af5b42a4f158.so
  = note: crate name: cargo_check_bug
  = note: crate name: cargo_check_bug

Steps to reprodroduce

git clone https://github.com/colin-kiegel/cargo_check_bug.git
cd cargo_check_bug
rustup override set nightly-2017-03-03
cargo clean && cargo test && cargo check
cargo clean && cargo check && cargo test

Result of Step 4

Everything OK!

   Compiling getopts v0.2.14
   Compiling libc v0.2.21
   Compiling bitflags v0.5.0
   Compiling rand v0.3.15
   Compiling pulldown-cmark v0.0.8
   Compiling tempdir v0.3.5
   Compiling skeptic v0.7.1
   Compiling cargo_check_bug v0.1.0 (file:///home/colin/projects/rust/cargo_check_bug)
    Finished dev [unoptimized + debuginfo] target(s) in 5.40 secs
     Running target/debug/deps/cargo_check_bug-bc124838e21e68e1
running 0 tests
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured
 Running target/debug/deps/skeptic-c3b458a20ebee641

running 1 test
warning: proc macro crates and #[no_link] crates have no effect without #[macro_use]
–> /tmp/rust-skeptic.9IqFqNCvwCPZ/test.rs:1:1
|
1 | extern crate cargo_check_bug;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
test readme_0 … ok
test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured
Doc-tests cargo_check_bug
running 0 tests
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured
Compiling cargo_check_bug v0.1.0 (file:///home/colin/projects/rust/cargo_check_bug)
Finished dev [unoptimized + debuginfo] target(s) in 0.12 secs

Result of Step 5

error[E0464]: multiple matching crates for `cargo_check_bug`

   Compiling bitflags v0.5.0
   Compiling getopts v0.2.14
   Compiling libc v0.2.21
   Compiling rand v0.3.15
   Compiling pulldown-cmark v0.0.8
   Compiling tempdir v0.3.5
   Compiling skeptic v0.7.1
   Compiling cargo_check_bug v0.1.0 (file:///home/colin/projects/rust/cargo_check_bug)
    Finished dev [unoptimized + debuginfo] target(s) in 4.54 secs
   Compiling cargo_check_bug v0.1.0 (file:///home/colin/projects/rust/cargo_check_bug)
    Finished dev [unoptimized + debuginfo] target(s) in 0.97 secs
     Running target/debug/deps/cargo_check_bug-bc124838e21e68e1
running 0 tests
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured
 Running target/debug/deps/skeptic-c3b458a20ebee641

running 1 test
error[E0464]: multiple matching crates for cargo_check_bug
–> /tmp/rust-skeptic.U89a9gBDNE36/test.rs:1:1
|
1 | extern crate cargo_check_bug;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: candidates:
= note: path: /home/colin/projects/rust/cargo_check_bug/target/debug/deps/libcargo_check_bug-0b76af5b42a4f158.so
= note: crate name: cargo_check_bug
= note: crate name: cargo_check_bug
error[E0463]: can’t find crate for cargo_check_bug
–> /tmp/rust-skeptic.U89a9gBDNE36/test.rs:1:1
|
1 | extern crate cargo_check_bug;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can’t find crate
error: aborting due to 2 previous errors
test readme_0 … FAILED
failures:
---- readme_0 stdout ----
thread ‘readme_0’ panicked at ‘Command failed:
“rustc” “/tmp/rust-skeptic.U89a9gBDNE36/test.rs” “–verbose” “-o” “/tmp/rust-skeptic.U89a9gBDNE36/out.exe” “–crate-type=bin” “-L” “/home/colin/projects/rust/cargo_check_bug/target/debug” “-L” “/home/colin/projects/rust/cargo_check_bug/target/debug/deps” “–extern” “pulldown_cmark=/home/colin/projects/rust/cargo_check_bug/target/debug/deps/libpulldown_cmark-ecfb67e72dcb6fb2.rlib” “–extern” “skeptic=/home/colin/projects/rust/cargo_check_bug/target/debug/deps/libskeptic-74b6fcba1ef2d3dc.rlib” “–extern” “getopts=/home/colin/projects/rust/cargo_check_bug/target/debug/deps/libgetopts-3facdbd0235704b0.rlib” “–extern” “tempdir=/home/colin/projects/rust/cargo_check_bug/target/debug/deps/libtempdir-0ee757a585f719dd.rlib” “–extern” “libc=/home/colin/projects/rust/cargo_check_bug/target/debug/deps/liblibc-5dc7b85e748840b4.rlib” “–extern” “bitflags=/home/colin/projects/rust/cargo_check_bug/target/debug/deps/libbitflags-8510a47beebe00a6.rlib” “–extern” “rand=/home/colin/projects/rust/cargo_check_bug/target/debug/deps/librand-c9d9fbdab2355ee4.rlib”’, /home/colin/.cargo/registry/src/github.com-1ecc6299db9ec823/skeptic-0.7.1/lib.rs:391
note: Run with RUST_BACKTRACE=1 for a backtrace.
failures:
readme_0
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured
error: test failed

`Cargo.toml`

[package]
name = "cargo_check_bug"
version = "0.1.0"
build = "build.rs"

[lib]
proc-macro = true

[dependencies]

[build-dependencies]
skeptic = "0.7"

[dev-dependencies]
skeptic = "0.7"

`build.rs`

extern crate skeptic;

fn main() {
    skeptic::generate_doc_tests(&["README.md"]);
}

`README.md`

```rust
extern crate cargo_check_bug;

fn main() {
}
```

`tests/skeptic.rs`

include!(concat!(env!("OUT_DIR"), "/skeptic-tests.rs"));

`src/lib.rs`

#![crate_type = "proc-macro"]
extern crate proc_macro;
use proc_macro::TokenStream;

#[proc_macro_derive(Foo)]
pub fn derive(_input: TokenStream) -> TokenStream {
    unimplemented!()
}

About this issue

Original URL
State: open
Created 7 years ago
Comments: 27 (13 by maintainers)

Commits related to this issue

Run "cargo clean" before "cargo test" Possible work-around for https://github.com/budziq/rust-skeptic/issues/18 — committed to aerospike/aerospike-client-rust by jhecking 6 years ago
feat: Put the test code inline into the test module This fixes two major issues with skeptic's current implementation at the cost of losing compile-fail tests. For many crates I expect this to be a w... — committed to Marwes/little-skeptic by Marwes 6 years ago

Most upvoted comments

Thanks for the feedback @budziq! I’m pretty far down this rabbit hole now, so I’ll see for myself the problems you encountered.

I do have an idea I mentioned in #8 for combining every test case into a single binary such that cargo build only needs to be executed once for the entire test set. That would hopefully be much faster than running cargo build for every test.

brson on Feb 13, 2019

I’ve started hacking on a fix for this that emits every test case as an individual cargo project, sharing the target directory with the “master” project.

brson on Feb 12, 2019

Oops, forgot to past back here about docmatic, my lite version based on people’s hacks here https://github.com/assert-rs/docmatic

epage on May 4, 2018

One plausible way to fix this would be to have skeptic synthesize an entire cargo project from the original cargo project, for every test it generates, sharing target directories. Then run cargo instead of rustc, and have cargo figure out the deps.

brson on Apr 8, 2017