Permission on macOS messed up

Question

I wanted to do npm install -g. As it didn't work due to permissions I took the approach suggested from the accepted answer in https://stackoverflow.com/questions/47252451/permission-denied-when-installing-npm-modules-in-osx

Change the owner of npm's directories to the name of the current user (your username):

sudo chown -R $(whoami) $(npm config get prefix)/{lib/node_modules,bin,share}

This changes the permissions of the sub-folders used by npm and some other tools (lib/node_modules, bin, and share).

then I could run my npm install -g. But this is not where the story ends. I wanted to install another package with npm. (npm install identicon).

I received the following error

npm does not support Node.js v12.0.0
You should probably upgrade to a newer version of node as we
can't make any promises that npm will work with this version.
You can find the latest version at https://nodejs.org/
....

And now I receive the same error over and over again, whenever I use a npm command.

On SO someone else had this issue https://stackoverflow.com/questions/56805007/npm-warn-npm-does-not-support-node-js-v12-4-0?noredirect=1&lq=1 and the accepted answer suggested

Fix /usr/local permissions:

sudo chown -R id -un:id -gn /usr/local

Clean npm cache and uninstall it:

npm cache clean -f npm -g uninstall npm

Reinstall node (with npm)

brew reinstall node

Upgrade npm:

npm -g i npm

But the very first command failed:

chown: /usr/local: Operation not permitted

In case this helps:

/usr/local root# ls -la


total 0
-rw-r--r--    1 myuser  staff      0 Sep 20  2019 .com.apple.installer.keep
drwxrwxr-x    2 myuser  staff     64 Apr 24  2019 Caskroom
drwxrwxr-x  103 myuser  staff   3296 Nov 17 17:31 Cellar
drwxrwxr-x    3 myuser  staff     96 Nov 17 17:25 Frameworks
drwxrwxr-x   22 myuser  staff    704 Jan 14 05:49 Homebrew
drwxrwxr-x  409 myuser  staff  13088 Jan 14 05:49 bin
drwxrwxr-x   10 myuser  staff    320 Nov 17 17:23 etc
drwxrwxr-x  192 myuser  staff   6144 Nov 17 17:33 include
drwxrwxr-x  620 myuser  staff  19840 Nov 17 17:33 lib
drwxr-xr-x    5 myuser  staff    160 Mar 24  2019 man
drwxrwxr-x  124 myuser  staff   3968 Nov 17 17:34 opt
drwxr-xr-x    3 myuser  staff     96 Mar 24  2019 remotedesktop
drwxrwxr-x   12 myuser  staff    384 Nov 17 17:27 sbin
drwxrwxr-x   34 myuser  staff   1088 Nov 17 17:34 share
drwxr-xr-x    4 myuser  staff    128 Mar 24  2019 texlive
drwxrwxr-x    4 myuser  staff    128 May 16  2021 var

I want to use npm again and have my permissions fixed. Maybe someone can point out good ressources for beginners, which can guide me through the process, when I experience something similar. Thank you.

My macbookpro: macOS Catalina (10.15.7)

Answer 1

You can use [nvm][1] to install node for your user in ~/ to avoid using the system node, which requires permissions. nvm allows you to install and switch between multiple versions of node.

As stated in the readme:

When using nvm you do not need sudo to globally install a module with npm -g, so instead of doing sudo npm install -g npm, do npm i -g npm

1. Prerequisites

Before you start, uninstall node if you have it installed with homebrew:

brew uninstall --ignore-dependencies node 
brew uninstall --force node

2. install nvm

Option 1: Using homebrew

Install nvm:

brew update
brew install nvm

Create the nvm directory:

mkdir ~/.nvm

Add the following to ~/.zshrc:

export NVM_DIR="${HOME}/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm

Option 2 (preferred): manual installation

To install nvm manually, download and run the install script and run it using either of the following cURL or Wget commands:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash

wget -qO- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash

If that doesn’t work, you can manually download the install script and run it.

This creates a directory for nvm in $HOME:

mkdir ~/.nvm

And adds source lines from the snippet below to~/.zshrc which loads nvm in every new terminal shell:

export NVM_DIR="$([ -z "${XDG_CONFIG_HOME-}" ] && printf %s "${HOME}/.nvm" || printf %s "${XDG_CONFIG_HOME}/nvm")"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm

3. Load nvm

You can either reset your current shell, start a new one, or source the .zshrc changes:

source ~/.zshrc

To verify that nvm has been installed, do:

command -v nvm

which should output nvm if the installation was successful.

4. Install node using nvm

Install node 14 using nvm and set it as the default version:

nvm install 14

Make node 14 the default version:

nvm alias default 14

Set default as the current version to use:

nvm use default

Upgrade npm installed for node 14 to the latest version:

npm install -g npm@latest