ProGet 2025.17: Errors building downloaded Cargo packages

[coboj59760_1341]

Hi! I'm using ProGet 2025.17 (Build 7) and am trying to set up ProGet as a proxy for https://crates.io. I've set up a Cargo feed and added a connector to https://crates.io.

However, when I try to build Rust code using ProGet as the registry, I get compilation errors that I don't get when using another registry, for example:

error[E0432]: unresolved import `once_cell::sync`
   --> /mypath/.cargo/registry/src/mydomain-f880e82129ec5ba0/tracing-core-0.1.34/src/lazy.rs:2:27
    |
  2 | pub(crate) use once_cell::sync::Lazy;
    |                           ^^^^ could not find `sync` in `once_cell`
    |
note: found an item that was configured out
   --> /mypath/.cargo/registry/src/mydomain-f880e82129ec5ba0/once_cell-1.21.3/src/lib.rs:863:9
    |
862 | #[cfg(any(feature = "std", feature = "critical-section"))]
    |          ----------------------------------------------- the item is gated here
863 | pub mod sync {
    |         ^^^^

I've done some debugging, and think I found the reason: ProGet seems to sometimes change the "default_features" flag of indirect dependencies, which causes Cargo to try to build the code with the incorrect features enabled.

As an example, this is (part of) what ProGet returns for http://mydomain/cargo/public-cargo/tr/ac/tracing-core (where public-cargo is my feed name):

... other versions
{
  "name": "tracing-core",
  "vers": "0.1.34",
  "deps": [
    {
      "name": "once_cell",
      "req": "1.13.0",
      "optional": true,
      "kind": "normal",
      "default_features": false,
      "features": [],
      "registry": null,
      "target": null
    },
    {
      "name": "valuable",
      "req": "0.1.0",
      "optional": true,
      "kind": "normal",
      "default_features": false,
      "features": [],
      "registry": null,
      "target": "cfg(tracing_unstable)"
    }
  ],
  "cksum": "b9d12581f227e93f094d3af2ae690a574abb8a2b9b7a96e7cfe9647b2b617678",
  "features": {
    "default": [
      "std",
      "valuable?/std"
    ],
    "std": [
      "once_cell"
    ]
  },
  "v": 2,
  "rust_version": "1.65.0",
  "yanked": false
}
... other versions

Note that for the "once_cell" dependency, "default_features" is false. However, getting the same package from crates.io (https://index.crates.io/tr/ac/tracing-core) returns:

... other versions
{
  "name": "tracing-core",
  "vers": "0.1.34",
  "deps": [
    {
      "name": "once_cell",
      "req": "^1.13.0",
      "features": [],
      "optional": true,
      "default_features": true,
      "target": null,
      "kind": "normal"
    },
    {
      "name": "valuable",
      "req": "^0.1.0",
      "features": [],
      "optional": true,
      "default_features": false,
      "target": "cfg(tracing_unstable)",
      "kind": "normal"
    }
  ],
  "cksum": "b9d12581f227e93f094d3af2ae690a574abb8a2b9b7a96e7cfe9647b2b617678",
  "features": {
    "std": [
      "once_cell"
    ]
  },
  "features2": {
    "default": [
      "std",
      "valuable?/std"
    ]
  },
  "yanked": false,
  "rust_version": "1.65.0",
  "v": 2
}
... other versions

Here, "once_cell"'s "default_features" is true. This doesn't seem to happen for all versions (only version 0.1.34 for the tracing-core crate).

I've found the same error for some other crates and versions:

• regex-automata (http://mydomain/cargo/public-cargo/re/ge/regex-automata) version 0.2: default_features is incorrectly set to false for dependencies fst, lazy_static, regex, regex-syntax, serde, serde_bytes, serde_derive and toml
• regex-automata (http://mydomain/cargo/public-cargo/re/ge/regex-automata) version 0.4.9: default_features is incorrectly set to false for dependencies anyhow, doc-comment, log and regex-test
• anyhow (http://mydomain/cargo/public-cargo/an/yh/anyhow) version 1.0.86: default_features is incorrectly set to false for dependencies backtrace, rustversion, syn, thiserror and trybuild

[rhessinger]

Hi @coboj59760_1341,

Thank you very much for all the information on how to recreate the error. In Cargo 1.84.0 (released in January 2025), they changed the default value for default_features from false to true. In the case of the examples you provided, these cargo manifests did specify a value for default_features causing it to change to false once the package is cached in ProGet.

I have created a ticket, PG-3182, to track the fix. This will be released in next weeks release of ProGet. I can also provide a pre-release version of ProGet if you would like. Just let me know!

Thanks,
Rich

[coboj59760_1341]

Hi @rhessinger,

Thanks for the quick reply. I'd love to try out a pre-release version when it's available.

[rhessinger]

Hi @coboj59760_1341,

I just pushed a pre-release that includes the fix. Please install ProGet 25.0.17-ci.12 and that should resolve this issue. Please let us know if that resolves your issue.

Thanks,
Rich

[coboj59760_1341]

Hi @rhessinger,

I just tested the pre-release and the build now works as expected. Thanks again for the quick fix!