Tracking Issue for Packages as (optional) namespaces

[epage]

Summary

RFC: #3243
Documentation: https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#open-namespaces
rustc tracking issue: rust-lang/rust#122349
crates.io tracking issue: rust-lang/crates.io#8292

Allow a parent package to open its API namespace for other packages to participate

Implementation

• Unstable flag (feat: Add 'open-namespaces' feature #13591)
• Allow one :: in the middle of package names, prevent publish (feat: Add 'open-namespaces' feature #13591)
• fix(pkgid): Allow open namespaces in PackageIdSpec's #14467
• Test cases
  • Depending on a package whose lib.name puts it in a namespace
  • Path or git dependency under a registry package namespace
  • Build scripts, see caeg-industries@f4305ca
• Publish support including index file system layout

Unresolved Issues

• For an implicit bin in a namespaced package, should do something (e.g. warn, error) about cross-platform hazard of :: being in the name?
• Should we allow renames like "foo::bar" = { package = "foo_bar", version = "1.0" } in Cargo.toml?
• How precisely should this be represented in the index trie?
• How we should name the .crate file / download URL

Future Extensions

No response

About tracking issues

Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.

[hydroperx]

I have created this simple package sunform::package1 with the open-namespaces feature enabled.

cargo-features = ["open-namespaces"]

[package]
...

sunform-package1.zip

When I initialize a Git repository in the local package, commit files, and run

cargo publish --allow-dirty

I get

    Updating crates.io index
error: failed to open: C:\Users\hydro\Downloads\Repositories\sunform-package1\target\package\.sunform::package1-0.1.0.crate

Caused by:
  A sintaxe do nome do arquivo, do nome do diretório ou do rótulo do volume está incorreta. (os error 123)

So for Windows these don't work yet?

[epage]

@hydroperfox publish support is not done yet, see this task from the task list

[ ] Publish support including index file system layout

[hydroperx]

I've remembered of binaries, where the default binary's name is derived from the package's name, in which case it requires translating :: to - (actually an underscore, not a hyphen) when writing the binary.