Current implementation cannot handle multiple crates with the same lib name

[baumanj]

When running cargo +nightly udeps against https://github.com/habitat-sh/habitat:

➤ cargo +nightly udeps
  Downloaded arc-swap v0.4.2
  Downloaded chrono v0.4.9
…
  Downloaded 34 crates (4.0 MB) in 8.13s (largest was `encoding_rs` at 1.4 MB)
Error: StrErr("current implementation cannot handle multiple crates with the same `lib` name:
`habitat_core v0.0.0 (/home/jbauman/habitat/components/core)`
├── "base64" → "base64"
├── "base64" → "base64"
└── ..")

I know

Crates are currently only handled on a per name basis. Two crates with the same name but different versions would be a problem.

is listed as a known bug in https://github.com/est31/cargo-udeps/blob/master/README.md#known-bugs, but I couldn't find an issue that's tracking it. Since the project I work on won't be able to make use of udeps until this is resolved, having an issue I can subscribe to will help ensure that I can use it when that bug is fixed.

[est31]

Yes, in this instance the crate is used both as build dependency and normal dependency. I've ran into this multiple times myself. Thanks for filing the bug.

[baumanj]

Thanks for the tool! It promises to be really helpful

[metajack]

I'm attempting to use this on https://github.com/libra/libra and it's failing with a similar error:

❯ cargo udeps
Error: StrErr("current implementation cannot handle multiple crates with the same `lib` name:
`admission_control_service v0.1.0 (/Users/metajack/src/libra/admission_control/admission_control_service)`
├── "admission_control_proto" → "admission_control_proto"
├── "admission_control_proto" → "admission_control_proto"
└── ..")

But admission_control_proto is not listed twice anywhere that I can see. Looks like the error message might be incorrect?

[est31]

PRs to fix it are welcome!

[qryxip]

@metajack The problem can be fixed by this. (I don't know why)

   for (to_pkg, deps) in resolve.deps(from) {
+     // `Resolve::deps` rarely returns multiple same `Dependenc`ies.
+     let deps = deps.iter().collect::<BTreeSet<_>>();

But unfortunately cargo-udeps still does not work for libra because admission_control_service depends on both futures v0.1 and futures v0.3.

Error: StrErr("current implementation cannot handle multiple crates with the same `lib` name:
`admission_control_service v0.1.0 (/home/ryo/src/libra/admission_control/admission_control_service)`
└── (dev-)dependencies
    ├── "futures03" → "futures"
    ├── "futures" → "futures"
    └── ..")

[dependencies]
futures = "0.1.28"
futures03 = { version = "=0.3.0-alpha.17", package = "futures-preview" }

[qryxip]

Still not working even though replacing futures v0.1 with futures01.
Though I wrote the error, The error should be probably a warning.

Error: StrErr("current implementation cannot handle multiple crates with the same `lib` name:
`libra_wallet v0.1.0 (/home/ryo/src/libra/client/libra_wallet)`
└── (dev-)dependencies
    ├── "rust-crypto" → "crypto"
    ├── "libra_crypto" → "crypto"
    └── ..")