SNAP run npm command

I installed node-red as a snap on ubuntu-core. It's an easy process and everything is working nicely except that I am not able to run npm command to manually install node.

For example automatic installation from browser of node-red-contrib-modbus is failing so I would like to use the recommended command :
npm install node-red-contrib-modbus --unsafe-perm --build-from-source

or if want to use" npm install" to automatically install all the node listed in packages.json.

This is more a problem related to snap than to node-red but if any of you have an idea...



The strict containerisation of snap means that although node and npm are installed inside the snap they aren't available outside... Also all the extra build tools to compile a node with binary options do not remain inside....

So the best way round is to build your own snap based off the master -

and edit the snapcraft.yaml file to add the extra nodes you want at build time - so it is packaged how you want it.

Thank you for the answer, if build my own snap it will no more update node-red automatically?