Prepare v4.0.17 release

Fixes #17379

The preprocessor we added to detect embedded languages uses a back
reference and given a long enough file with certain byte / character
patterns it'll cause what appears to be an indefinite hang (might just
be catastrophically exponential backtracking but not sure)

This replaces the one regex w/ back references with two, anchored,
multi-line regexes

Now we search for all the starting & ending delimiters in the file. We
then loop over all the starting delimiters, find the paired ending one,
and preprocess the content inside

---------

Co-authored-by: Philipp Spiess <hello@philippspiess.com>

CHANGELOG.md

@@ -20,6 +20,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - _Experimental_: Add `wrap-anywhere`, `wrap-break-word`, and `wrap-normal` utilities ([#12128](https://github.com/tailwindlabs/tailwindcss/pull/12128))
 - _Experimental_: Add `@source inline(…)` ([#17147](https://github.com/tailwindlabs/tailwindcss/pull/17147))
 
+## [4.0.17] - 2025-03-26
+
+### Fixed
+
+- Fix an issue causing the CLI to hang when processing Ruby files ([#17383](https://github.com/tailwindlabs/tailwindcss/pull/17383))
+
 ## [4.0.16] - 2025-03-25
 
 ### Added
@@ -3577,7 +3583,8 @@ No release notes
 
 - Everything!
 
-[unreleased]: https://github.com/tailwindlabs/tailwindcss/compare/v4.0.16...HEAD
+[unreleased]: https://github.com/tailwindlabs/tailwindcss/compare/v4.0.17...HEAD
+[4.0.17]: https://github.com/tailwindlabs/tailwindcss/compare/v4.0.16...v4.0.17
 [4.0.16]: https://github.com/tailwindlabs/tailwindcss/compare/v4.0.15...v4.0.16
 [4.0.15]: https://github.com/tailwindlabs/tailwindcss/compare/v4.0.14...v4.0.15
 [4.0.14]: https://github.com/tailwindlabs/tailwindcss/compare/v4.0.13...v4.0.14

Cargo.lock

@@ -27,21 +27,6 @@ dependencies = [
  "nom",
 ]
 
-[[package]]
-name = "bit-set"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08807e080ed7f9d5433fa9b275196cfc35414f66a0c79d864dc51a0d825231a3"
-dependencies = [
- "bit-vec",
-]
-
-[[package]]
-name = "bit-vec"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
-
 [[package]]
 name = "bitflags"
 version = "2.6.0"
@@ -171,17 +156,6 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
-[[package]]
-name = "fancy-regex"
-version = "0.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e24cb5a94bcae1e5408b0effca5cd7172ea3c5755049c5f3af4cd283a165298"
-dependencies = [
- "bit-set",
- "regex-automata 0.4.8",
- "regex-syntax 0.8.5",
-]
-
 [[package]]
 name = "fast-glob"
 version = "0.4.3"
@@ -564,7 +538,6 @@ dependencies = [
  "classification-macros",
  "crossbeam",
  "dunce",
- "fancy-regex",
  "fast-glob",
  "globwalk",
  "ignore",

crates/node/npm/android-arm-eabi/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-android-arm-eabi",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/android-arm64/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-android-arm64",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/darwin-arm64/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-darwin-arm64",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/darwin-x64/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-darwin-x64",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/freebsd-x64/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-freebsd-x64",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/linux-arm-gnueabihf/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-linux-arm-gnueabihf",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/linux-arm64-gnu/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-linux-arm64-gnu",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/linux-arm64-musl/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-linux-arm64-musl",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/linux-x64-gnu/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-linux-x64-gnu",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/linux-x64-musl/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-linux-x64-musl",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/win32-arm64-msvc/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-win32-arm64-msvc",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/npm/win32-x64-msvc/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide-win32-x64-msvc",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/node/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/oxide",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/tailwindlabs/tailwindcss.git",

crates/oxide/Cargo.toml

@@ -19,8 +19,6 @@ bexpand = "1.2.0"
 fast-glob = "0.4.3"
 classification-macros = { path = "../classification-macros" }
 regex = "1.11.1"
-fancy-regex = "0.14.0"
 
 [dev-dependencies]
 tempfile = "3.13.0"
-

crates/oxide/src/extractor/pre_processors/ruby.rs

@@ -4,12 +4,22 @@ use crate::cursor;
 use crate::extractor::bracket_stack;
 use crate::extractor::pre_processors::pre_processor::PreProcessor;
 use crate::pre_process_input;
-use bstr::ByteSlice;
-use fancy_regex::Regex;
+use bstr::ByteVec;
+use regex::{Regex, RegexBuilder};
 use std::sync;
 
-static TEMPLATE_REGEX: sync::LazyLock<Regex> = sync::LazyLock::new(|| {
-    Regex::new(r#"\s*(.*?)_template\s*<<[-~]?([A-Z]+?)\n([\s\S]*?)\2"#).unwrap()
+static TEMPLATE_START_REGEX: sync::LazyLock<Regex> = sync::LazyLock::new(|| {
+    RegexBuilder::new(r#"\s*([a-z0-9_-]+)_template\s*<<[-~]?([A-Z]+)$"#)
+        .multi_line(true)
+        .build()
+        .unwrap()
+});
+
+static TEMPLATE_END_REGEX: sync::LazyLock<Regex> = sync::LazyLock::new(|| {
+    RegexBuilder::new(r#"^\s*([A-Z]+)"#)
+        .multi_line(true)
+        .build()
+        .unwrap()
 });
 
 #[derive(Debug, Default)]
@@ -25,14 +35,44 @@ impl PreProcessor for Ruby {
         // Extract embedded template languages
         // https://viewcomponent.org/guide/templates.html#interpolations
         let content_as_str = std::str::from_utf8(content).unwrap();
-        for capture in TEMPLATE_REGEX
+
+        let starts = TEMPLATE_START_REGEX
             .captures_iter(content_as_str)
-            .filter_map(Result::ok)
-        {
-            let lang = capture.get(1).unwrap().as_str();
-            let body = capture.get(3).unwrap().as_str();
-            let replaced = pre_process_input(body.as_bytes(), lang);
-            result = result.replace(body, replaced);
+            .collect::<Vec<_>>();
+        let ends = TEMPLATE_END_REGEX
+            .captures_iter(content_as_str)
+            .collect::<Vec<_>>();
+
+        for start in starts.iter() {
+            // The language for this block
+            let lang = start.get(1).unwrap().as_str();
+
+            // The HEREDOC delimiter
+            let delimiter_start = start.get(2).unwrap().as_str();
+
+            // Where the "body" starts for the HEREDOC block
+            let body_start = start.get(0).unwrap().end();
+
+            // Look through all of the ends to find a matching language
+            for end in ends.iter() {
+                // 1. This must appear after the start
+                let body_end = end.get(0).unwrap().start();
+                if body_end < body_start {
+                    continue;
+                }
+
+                // The languages must match otherwise we haven't found the end
+                let delimiter_end = end.get(1).unwrap().as_str();
+                if delimiter_end != delimiter_start {
+                    continue;
+                }
+
+                let body = &content_as_str[body_start..body_end];
+                let replaced = pre_process_input(body.as_bytes(), &lang.to_ascii_lowercase());
+
+                result.replace_range(body_start..body_end, replaced);
+                break;
+            }
         }
 
         // Ruby extraction

packages/@tailwindcss-browser/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/browser",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "description": "A utility-first CSS framework for rapidly building custom user interfaces.",
   "license": "MIT",
   "main": "./dist/index.global.js",

packages/@tailwindcss-cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/cli",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "description": "A utility-first CSS framework for rapidly building custom user interfaces.",
   "license": "MIT",
   "repository": {

packages/@tailwindcss-node/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/node",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "description": "A utility-first CSS framework for rapidly building custom user interfaces.",
   "license": "MIT",
   "repository": {

packages/@tailwindcss-postcss/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/postcss",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "description": "PostCSS plugin for Tailwind CSS, a utility-first CSS framework for rapidly building custom user interfaces",
   "license": "MIT",
   "repository": {

packages/@tailwindcss-standalone/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/standalone",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "private": true,
   "description": "Standalone CLI for Tailwind CSS",
   "license": "MIT",

packages/@tailwindcss-upgrade/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/upgrade",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "description": "A utility-first CSS framework for rapidly building custom user interfaces.",
   "license": "MIT",
   "repository": {

packages/@tailwindcss-vite/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tailwindcss/vite",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "description": "A utility-first CSS framework for rapidly building custom user interfaces.",
   "license": "MIT",
   "repository": {

packages/tailwindcss/package.json

@@ -1,6 +1,6 @@
 {
   "name": "tailwindcss",
-  "version": "4.0.16",
+  "version": "4.0.17",
   "description": "A utility-first CSS framework for rapidly building custom user interfaces.",
   "license": "MIT",
   "repository": {