Ubuntu – npm not really uninstalling global package

My npm version is 5.0.3 and I have the same problem when I use any npm command:

The command is working fine but this code keeps showing up for no apparent reason. I've updated from 5.0.3 to 5.2.0 with these commands:

sudo chown -R $USER:$(id -gn $USER) /home/sagar/.config

npm install -g npm or npm i -g npm.

Now npm is working fine.

TLDR: This problem is caused by Bash caching the path of the npm command, and can be solved by hash -d npm. You don't even need to deal with apt purge unless you want to.

Explanation

Here were my steps for getting a new npm version on Ubuntu. First, do the installation as OP describes:

$ sudo apt-get install npm
(...apt installation of npm was successful...)
$ npm -v
3.5.2
$ command -v npm
/usr/bin/npm
$ sudo npm install -g npm
(...npm installation of npm was successful...so far, so good)

You can see that the new version is already working fine in /usr/local/bin/npm, but unfortunately the Bash cache still has /usr/bin/npm:

$ /usr/local/bin/npm -v
6.4.1
$ npm -v
3.5.2
$ command -v npm
/usr/bin/npm
$ type npm
npm is hashed (/usr/bin/npm)

To fix the problem, clear it from the Bash cache (do this in all open shells):

$ hash -d npm

Now the new version works as desired:

$ npm -v
6.4.1
$ command -v npm
/usr/local/bin/npm