Merge pull request #435 from flip1995/clippy_plugin

Blog post on removing the Clippy plugin interface

Author: nikomatsakis

posts/inside-rust/2019-11-04-Clippy-removes-plugin-interface.md

@@ -0,0 +1,59 @@
+---
+layout: post
+title: "Clippy is removing its plugin interface"
+author: Philipp Krones
+description: "Now that compiler plugins are deprecated, Clippy is removing its deprecated plugin interface"
+team: the Dev tools team (Clippy) <https://www.rust-lang.org/governance/teams/dev-tools#clippy>
+---
+
+Today, we're announcing that Clippy will completely remove its plugin interface.
+Using the plugin interface has been deprecated for about one and a half year now
+([rust-lang/rust-clippy#2712]). Since then, an unsilenceable warning has been
+emitted. Now that compiler plugins are officially deprecated
+([rust-lang/rust#64675]), Clippy will remove its support for the plugin
+interface completely ([rust-lang/rust-clippy#4714]). This change will hit stable
+with version 1.41.0.
+
+[rust-lang/rust-clippy#2712]: https://github.com/rust-lang/rust-clippy/pull/2712
+[rust-lang/rust#64675]: https://github.com/rust-lang/rust/pull/64675
+[rust-lang/rust-clippy#4714]: https://github.com/rust-lang/rust-clippy/pull/4714
+
+### Does this post affect me?
+
+Most likely, no. This post only affects you, if you're still using Clippy
+through its plugin interface. If you do so, you get the warning
+
+```
+warning: the clippy plugin is being deprecated, please use cargo clippy or rls with the clippy feature
+```
+
+when compiling your crate. If you don't see this warning, nothing will change
+for you.
+
+### How do I migrate from the plugin interface?
+
+If you are still using the Clippy plugin interface, here are some steps you can
+take to migrate to `cargo clippy`.
+
+1. `Cargo.toml`: Remove every occurrence of the `clippy` dependency and the
+   `clippy` feature.
+2. Completely remove every occurrence of `feature(plugin)` and `plugin(clippy)`.
+3. Replace every occurrence of `feature = "clippy"` with `feature =
+   "cargo-clippy"`. The `cargo-clippy` feature is automatically enabled when
+   running `cargo clippy`.
+4. CI: You now have to install Clippy via rustup, with `rustup component add
+   clippy`. Once installed, you can run `cargo clippy` (for more usage
+   instructions, see the [Clippy `README`]). Note that Clippy is not included in
+   every nightly, but you can check its availability on the [rustup components
+   history] page.
+
+[Clippy `README`]: https://github.com/rust-lang/rust-clippy#usage
+[rustup components history]: https://rust-lang.github.io/rustup-components-history/index.html
+
+### Where should I go if I have more questions?
+
+If you need help with migrating from the plugin interface, you can contact us
+via [Discord] or open an issue on [GitHub].
+
+[Discord]: https://discord.gg/vNNtpyD
+[GitHub]: https://github.com/rust-lang/clippy/issues/new