Ignore content files that don't exist (#6901)

* ignore content files that don't exist

PostCSS CLI will give you a fake file path that ends in /stdin if you
are reading from stdin.

* update changelog

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Preserve case of css variables added by plugins ([#6888](https://github.com/tailwindlabs/tailwindcss/pull/6888))
+- Ignore content files that don't exist ([#6901](https://github.com/tailwindlabs/tailwindcss/pull/6901))
 
 ## [3.0.10] - 2022-01-04
 

src/lib/setupContextUtils.js

@@ -435,7 +435,14 @@ function trackModified(files, fileModifiedMap) {
     let parsed = url.parse(file)
     let pathname = parsed.hash ? parsed.href.replace(parsed.hash, '') : parsed.href
     pathname = parsed.search ? pathname.replace(parsed.search, '') : pathname
-    let newModified = fs.statSync(decodeURIComponent(pathname)).mtimeMs
+    let newModified = fs.statSync(decodeURIComponent(pathname), { throwIfNoEntry: false })?.mtimeMs
+    if (!newModified) {
+      // It could happen that a file is passed in that doesn't exist. E.g.:
+      // postcss-cli will provide you a fake path when reading from stdin. This
+      // path then looks like /path-to-your-project/stdin In that case we just
+      // want to ignore it and don't track changes at all.
+      continue
+    }
 
     if (!fileModifiedMap.has(file) || newModified > fileModifiedMap.get(file)) {
       changed = true