# Known issues

> Known issues when installing Docsy theme.

---

The following issues are known on [MacOS](#macos) and on
[Windows Subsystem for Linux](#windows-subsystem-for-linux-wsl):

### MacOS

#### Errors: `too many open files` or `fatal error: pipe failed`

By default, MacOS permits a small number of open File Descriptors. For larger
sites, or when you're simultaneously running multiple applications, you might
receive one of the following errors when you run
[`hugo server`](https://gohugo.io/commands/hugo_server/) to preview your site
locally:

- POSTCSS v7 and earlier:

  ```
  ERROR 2020/04/14 12:37:16 Error: listen tcp 127.0.0.1:1313: socket: too many open files
  ```

- POSTCSS v8 and later:

  ```
  fatal error: pipe failed
  ```

##### Workaround

To temporarily allow more open files:

1. View your current settings by running:

   ```
   sudo launchctl limit maxfiles
   ```

2. Increase the limit to `65535` files by running the following commands. If
   your site has fewer files, you can choose to set lower soft (`65535`) and
   hard (`200000`) limits.

   ```shell
   sudo launchctl limit maxfiles 65535 200000
   ulimit -n 65535
   sudo sysctl -w kern.maxfiles=200000
   sudo sysctl -w kern.maxfilesperproc=65535
   ```

Note that you might need to set these limits for each new shell.
[Learn more about these limits and how to make them permanent](https://www.google.com/search?q=mac+os+launchctl+limit+maxfiles+site%3Aapple.stackexchange.com&oq=mac+os+launchctl+limit+maxfiles+site%3Aapple.stackexchange.com).

### Windows Subsystem for Linux (WSL)

If you're using WSL, ensure that you're running `hugo` on a Linux mount of the
filesystem, rather than a Windows one, otherwise you may get unexpected errors.