cuando trato de hacer esto:

brew install node

Recibo este mensaje:

 /usr/local/Homebrew/Library/Homebrew/utils/lock.sh: line 19: /usr/local/var/homebrew/locks/update: Permission denied
-e:1:in `initialize': Bad file descriptor (Errno::EBADF)
    from -e:1:in `new'
    from -e:1:in `<main>'
Error: Another active Homebrew process is already in progress.
Please wait for it to finish or terminate it to continue.
Error: Permission denied - /usr/local/var/homebrew/locks/node.brewing

¿Alguna idea sobre cómo resolver?

Gracias