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| <h1 id="writing-an-rfc"><a class="header" href="#writing-an-rfc">Writing an RFC</a></h1> |
| <p>Generally, an RFC goes through:</p> |
| <ol> |
| <li>Pre-RFC discussions on the <a href="https://internals.rust-lang.org/">internals forum</a></li> |
| <li><a href="https://github.com/rust-lang/rfcs/">RFC</a></li> |
| <li><a href="unstable.html">Development and stabilization</a></li> |
| </ol> |
| <p>Please keep in mind our <a href="../design.html">design principles</a>.</p> |
| <p>For more concrete areas of consideration:</p> |
| <h2 id="cargoconfigtoml-and-cargotoml"><a class="header" href="#cargoconfigtoml-and-cargotoml"><code>.cargo/config.toml</code> and <code>Cargo.toml</code></a></h2> |
| <p><code>.cargo/config.toml</code> is for environment or transient configuration, |
| being dependent on what directory you are running from and settable on the command-line, |
| independent of other flags like <code>--manifest-path</code> or <code>--package</code>.</p> |
| <p>On the other hand <code>Cargo.toml</code> is for static, high-level project configuration.</p> |
| <p>For example,</p> |
| <ul> |
| <li><a href="https://rust-lang.github.io/rfcs/3537-msrv-resolver.html">RFC 3537</a> chose |
| configuration for the MSRV-aware resolver because users would likely need |
| to change this setting, like in CI to verify the opposite case of |
| what they run by default.</li> |
| <li>The Cargo team rejected a <a href="https://github.com/rust-lang/cargo/pull/11631#issuecomment-1487424886"><code>[cfg]</code> table</a> to represent <code>rustc</code> |
| <code>--cfg</code> flags as it was a direct port of low-level rustc behavior that didn’t |
| mesh with the other high level abstractions of manifests. |
| <ul> |
| <li>For stabilization, this was worked around through a build script directive and a <code>[lints]</code> field configuration.</li> |
| </ul> |
| </li> |
| <li><a href="https://github.com/rust-lang/cargo/issues/12738">#12738</a> for exploring how existing config might be representable in <code>Cargo.toml</code>.</li> |
| </ul> |
| <h2 id="cargotoml"><a class="header" href="#cargotoml"><code>Cargo.toml</code></a></h2> |
| <p>When adding a table to a manifest,</p> |
| <ul> |
| <li>Should it be inheritable?</li> |
| <li>Ensure the package table and the inheritable table under <code>workspace</code> align</li> |
| <li>Care is needed to ensure a <code>workspace = true</code> field doesn’t conflict with other entries |
| <ul> |
| <li>e.g. <a href="https://rust-lang.github.io/rfcs/3389-manifest-lint.html">RFC 3389</a> had to explicitly exclude ever supporting a <code>workspace</code> linter</li> |
| </ul> |
| </li> |
| </ul> |
| <p>When adding a field,</p> |
| <ul> |
| <li>Is it inheritable? |
| <ul> |
| <li>Consider whether sharing of the field would be driven by requirements or is a manifestation of the current implementation. |
| For example, in most cases, dependency sources (e.g. <code>version</code> field) should be aligned across a workspace |
| However, frequently dependency <code>features</code> will vary across a workspace.</li> |
| </ul> |
| </li> |
| <li>When inheriting, can specify it in your package?</li> |
| <li>How does specifying a field in both <code>workspace</code> and a package interact? |
| <ul> |
| <li>e.g. dependency sources cannot be overridden</li> |
| <li>e.g. dependency <code>features</code> get merged</li> |
| <li>e.g. dependency <code>default-features</code> has been hard to get right (<a href="https://github.com/rust-lang/cargo/issues/12162">#12162</a>)</li> |
| </ul> |
| </li> |
| </ul> |
| <p>When working extending <code>dependencies</code> tables:</p> |
| <ul> |
| <li>How does this affect <code>cargo add</code> or <code>cargo remove</code>?</li> |
| <li>How does this affect <code>[patches]</code> which are just modified dependencies?</li> |
| </ul> |
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