[vite] Internal server error: Cannot read property 'length' of undefined

[cllemon]

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Describe the bug

In the vue project created with vite (jsx added):

npm run dev

Output:

2:36:51 PM [vite] Internal server error: Cannot read property 'length' of undefined
      at posToNumber (/Users/kite/vite/packages/vite/src/node/utils.ts:204:23)
      at Object.generateCodeFrame (/Users/kite/vite/packages/vite/src/node/utils.ts:237:11)
      at formatError (/Users/kite/vite/packages/vite/src/node/server/pluginContainer.ts:311:34)
      at TransformContext.error (/Users/kite/vite/packages/vite/src/node/server/pluginContainer.ts:276:13)
      at Object.transform (/Users/kite/vite/packages/vite/src/node/server/pluginContainer.ts:521:15)

After investigation, the css code in the .less file references an undefined variable.
However, vite’s internal error information covers the valuable error information needed.

Expected output:

2:35:54 PM [vite] Internal server error: variable @mini-heights is undefined
  Plugin: vite:css
  File: /Users/kite/my-vue-app/src/styles/index.less
      at less (/Users/kite/vite/packages/vite/src/node/plugins/css.ts:533:42)
      at compileCSS (/Users/kite/vite/packages/vite/src/node/plugins/css.ts:329:36)
      at TransformContext.transform (/Users/kite/vite/packages/vite/src/node/plugins/css.ts:88:42)
      at Object.transform (/Users/kite/vite/packages/vite/src/node/server/pluginContainer.ts:517:20)
      at Object.transformRequest (/Users/kite/vite/packages/vite/src/node/server/transformRequest.ts:123:27)
      at /Users/kite/vite/packages/vite/src/node/server/middlewares/transform.ts:119:24

Reproduction

https://github.com/cllemon/my-vue-app

System Info

• vite version: v2.0.0-beta.34
• Operating System: MacOS Catalina v10.15.5
• Node version: v12.13.0
• Package manager (npm/yarn/pnpm) and version: npm v6.14.4

Logs (Optional if provided reproduction)

2:36:51 PM [vite] Internal server error: Cannot read property 'length' of undefined
      at posToNumber (/Users/kite/vite/packages/vite/src/node/utils.ts:204:23)
      at Object.generateCodeFrame (/Users/kite/vite/packages/vite/src/node/utils.ts:237:11)
      at formatError (/Users/kite/vite/packages/vite/src/node/server/pluginContainer.ts:311:34)
      at TransformContext.error (/Users/kite/vite/packages/vite/src/node/server/pluginContainer.ts:276:13)
      at Object.transform (/Users/kite/vite/packages/vite/src/node/server/pluginContainer.ts:521:15)