warning: output filename collision

[wdanilo]

Problem

Hi, let's imagine I have this siutation:

workspace:

• Cargo.toml (members: [crates/*])
• crates
  • lib/Cargo.toml
  • macro/Cargo.toml
  • helper/Cargo.toml

Now, lib imports helper and macro imports helper. When I build it, cargo tells me:

output filename collision.
The lib target `helper` in package `helper v1.0.0 (<mylib>/crates/helper)` has the same output filename as the lib target `helper` in package `helper v1.0.0 (<mylib>/crates/helper)`.
Colliding filename is: <mylib>/target/release/deps/libhelper.rlib
The targets should have unique names.

And I believe this is because lib and macro use other rustc config to compile their targets. What to do in this situation?

Steps

1. Replicate struct shown above.

Possible Solution(s)

None so far

Notes

No response

Version

cargo 1.85.0-nightly (c86f4b3a1 2024-12-24)

[weihanglo]

Thanks for the report! Do you have a minimal reproducible example we can inspect? Like a Git repo, or a zip file would help. IIRC, rlib under target/release/deps/ directory shouldn't collide with each others, so I am curious.

[weihanglo]

Anyway, there is a mega tracking issue of this #6313.

[wdanilo]

I just realized it happens only when shared target contains cdylib. Without it, it compiles fine. The minimal repro is basically empty libs as described above.

[weihanglo]

Without knowing the content of each Cargo.toml file, I cannot really reproduce it. That said, you mentioned cdylib so I can guess from that crate-type being set as cdylib. Dylib filename collision is tracked in #6313, so close in favor of that. Let us know if there is a reason to keep this open separately.