Lib.rs

::cratesio-placeholder-package

If there is nothing in a crate, then a fortiori, there is nothing wrong with it either!

If you depend on a crate and it is empty, did you really depend on that crate?

Rationale

Sometimes you may want to publish a crate having a private / git / local dependency, which is useful for local or experimental development stuff, but which prevents your crate from being published.

In that case, you can use this hack empty placeholder package in its stead:

# Cargo.toml

[dependencies.your-crate-proxy]
# What public / crates.io users will see/use:
package = "cratesio-placeholder-package"
version = "=0.0.0"

# What `path` dependents will use
path = "path/to/your-crate-proxy"

and then have a your-crate-proxy crate, at version 0.0.0, somewhere in your private project layout, which correctly depends on the other private stuff you may need.

# path/to/your-crate-proxy/Cargo.toml

[package]
name = "cratesio-placeholder-package"
version = "0.0.0"

[dependencies]
# the real private dependency(ies)
your-crate.path = "private/your-crate"

Feature: proxying Cargo features

# Cargo.toml
[features]
foo = ["your-crate-proxy/placeholder-feature-a"]

[dependencies.your-crate-proxy]
# What public / crates.io users will see/use:
package = "cratesio-placeholder-package"
version = "=0.0.0"

# What `path` dependents will use
path = "path/to/your-crate-proxy"

# path/to/your-crate-proxy/Cargo.toml
[package]
name = "cratesio-placeholder-package"
version = "0.0.0"

[dependencies]
# the real private dependency(ies)
your-crate.path = "private/your-crate"

[features]
placeholder-feature-a = ["your-crate/foo"]