> ## Content Index
> Fetch the complete content index at: https://til.codes/llms.txt
> Use this file to discover other available public pages before exploring further.

# brew cask: Error: Unknown command: cask
- URL: https://til.codes/brew-cask-error-unknown-command-cask/
- Published: 2016-09-24T14:45:08.000Z
- Updated: 2016-09-24T14:45:08.000Z
- Author: Manu Ajith
- Tags: osx, brew, #Import 2024-07-13 21:01

After upgrading my OS to Sierra I was having an issue with homebrew. It failed to recognize the `cask` command and was throwing an error:

```
brew cask install haskell-platform
Error: Unknown command: cask

```

Brew wasn't able to find the correct path and was causing this issue.

### Fix:

```
brew update
brew cleanup
brew cask cleanup

```