Another active Homebrew process is already in progress

Question

Try removing the Homebrew process locks with this command:

rm -rf /usr/local/var/homebrew/locks

As this thread suggests at some point, my problem was to run brew command with sudo privileges for the first time. This causes brew to try to access privileged files and folders and it fails. If that's the case for you, run these commands and try installing node again.

sudo chown -R "$USER":admin /usr/local

brew cleanup

just close the terminal and reopen another

Simply type the following into your terminal:

brew cleanup

This should clean up any issues. Follow the command with:

brew doctor

All done.

In my case on OSX, I interrupted node install and then I try to start install node again so I got the error mentioned in the question.
I tried below steps from other responses:

sudo chown -R "$USER":admin /usr/local

brew cleanup

and

rm -rf /usr/local/var/homebrew/locks

but this message appear again - so don't know if above steps helped.

Then I closed the terminal tab and in new one ran

brew install -v node

It took 11 minutes to finish successfully node installation

Change file permission will avoid this error:

sudo chown <your-username>:admin /usr/local/Homebrew/Library/Homebrew/utils/lock.sh

For permission issues with homebrew install or update:

Change your homebrew permission setting

sudo chown -R <your-username>:admin /usr/local/Homebrew

sudo chown -R <your-username>:admin /usr/local/var/homebrew

Then run homebrew install or update