File already exists error when building

Bug report

Describe the bug

A clear and concise description of what the bug is.

When I run npx next build in my Next.js project, I come up with this error:

> Build error occurred
{ [Error: EEXIST: file already exists, mkdir '/home/nchiang/repos/covid-tutoring/.next']
  errno: -17,
  code: 'EEXIST',
  syscall: 'mkdir',
  path: '/home/nchiang/repos/covid-tutoring/.next' }

When I remove that .next directory, I come up with a similar error:

> next build

Creating an optimized production build ...fs.js:115
    throw err;
    ^

Error: EEXIST: file already exists, mkdir '/home/nchiang/repos/covid-tutoring/.next/cache/next-minifier'
    at mkdirSync (fs.js:731:3)
    at new TaskRunner (/home/nchiang/repos/covid-tutoring/node_modules/next/dist/build/webpack/plugins/terser-webpack-plugin/src/TaskRunner.js:1:634)
    at TerserPlugin.optimizeFn (/home/nchiang/repos/covid-tutoring/node_modules/next/dist/build/webpack/plugins/terser-webpack-plugin/src/index.js:6:1316)
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/home/nchiang/repos/covid-tutoring/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:21:1)
    at AsyncSeriesHook.lazyCompileHook (/home/nchiang/repos/covid-tutoring/node_modules/tapable/lib/Hook.js:154:20)
    at hooks.additionalAssets.callAsync.err (/home/nchiang/repos/covid-tutoring/node_modules/webpack/lib/Compilation.js:1409:36)
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/home/nchiang/repos/covid-tutoring/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:6:1)
    at AsyncSeriesHook.lazyCompileHook (/home/nchiang/repos/covid-tutoring/node_modules/tapable/lib/Hook.js:154:20)
    at hooks.optimizeTree.callAsync.err (/home/nchiang/repos/covid-tutoring/node_modules/webpack/lib/Compilation.js:1405:32)
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/home/nchiang/repos/covid-tutoring/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:6:1)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! root@ build: `next build`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the root@ build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/nchiang/.npm/_logs/2020-04-02T15_16_25_792Z-debug.log

I’m guessing that this has something to do with fs.

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

1. Clone this repository
2. Install dependencies with npm i
3. Run npm run build or npx next build
4. See error

Expected behavior

A clear and concise description of what you expected to happen.

Running npm run build or npx next build should build the app for production usage.

System information

• OS: Ubuntu 18.04.2
• Version of Next.js: ^9.3.4

[ijjk]

Hi, what version of Node.js are you using where you are seeing this error? Next.js v9.3.4 requires Node.js >= 10 as mentioned in the System Requirements and using a lower version of Node.js may be the reason you are seeing this error

[ijjk]

Node.js v10.10.0 is just slightly under the required version and v10.13.0 is needed. Since this can cause some confusion we can make sure to specify this exact version as the minimum required version in our docs.

Note: yarn v1 can help catch these slight incompatibilities