From d77f5538c2fa1d86ea0dd5872bff08eea8be8c00 Mon Sep 17 00:00:00 2001
From: Masafumi Koba <473530+ybiquitous@users.noreply.github.com>
Date: Mon, 15 Jul 2019 19:08:06 +0900
Subject: [PATCH] fix: fix PostCSS warning on `build` command (#1664)

The warning is produced on `cssnano` call. See below:

> Without `from` option PostCSS could generate wrong source map and will not find Browserslist config. Set it to CSS file path or to `undefined` to prevent this warning.

Reproduction:

```shell
mkdir work
cd work
npx docusaurus-init
cd website
yarn install
yarn run build
```

Environments:

- Node: 12.6.0
- Yarn: 1.17.3
---
 packages/docusaurus-1.x/lib/server/utils.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/docusaurus-1.x/lib/server/utils.js b/packages/docusaurus-1.x/lib/server/utils.js
index 905ffb883707..54c409248303 100644
--- a/packages/docusaurus-1.x/lib/server/utils.js
+++ b/packages/docusaurus-1.x/lib/server/utils.js
@@ -53,6 +53,7 @@ function minifyCss(cssContent) {
     .process(cssContent, {
       preset: 'default',
       zindex: false,
+      from: undefined,
     })
     .then(result => result.css);
 }