ln: /usr/local/bin/*: Permission denied

[salimane]

While installing some brewcask osx apps , these errors were thrown...

Error: Execution of 'brew cask install github --appdir=/Applications' returned 1: ==> Downloading https://central.github.com/mac/latest
Already downloaded: /Library/Caches/Homebrew/github-latest
==> It seems there is already an App at '/Applications/GitHub.app'; not linking.
==> Symlinking Binary 'github_cli' to '/usr/local/bin/github'
Error: Command failed to execute!

==> Failed command:
["/bin/ln", "-hfs", "--", "#<Pathname:/opt/homebrew-cask/Caskroom/github/latest/GitHub.app/Contents/MacOS/github_cli>", "#<Pathname:/usr/local/bin/github>"]

==> Output of failed command:


==> Exit status of failed command:
#<Process::Status: pid 91787 exit 1>
==> ln: /usr/local/bin/github: Permission denied

Is it impossible to install some apps with brewcask if there were already installed ?
Thanks

[radeksimko]

This is a valid issue, but it belongs to the upstream repo and it's actually already there.
Homebrew/homebrew-cask#7750