Ho provato a installare nodejs e npm su Ubuntu 12.04. Ho cercato su google e l'ho fatto. Ora, non ho potuto installare npm sulla macchina.
sudo apt-get install npm
Il che mi dà questo
The following packages have unmet dependencies:
npm : Depends: nodejs but it is not going to be installed
Depends: nodejs-dev
Depends: node-request but it is not going to be installed
Depends: node-mkdirp but it is not going to be installed
Depends: node-minimatch but it is not going to be installed
Depends: node-semver but it is not going to be installed
Depends: node-ini but it is not going to be installed
Depends: node-graceful-fs but it is not going to be installed
Depends: node-abbrev but it is not going to be installed
Depends: node-nopt but it is not going to be installed
Depends: node-fstream but it is not going to be installed
Depends: node-rimraf but it is not going to be installed
Depends: node-tar but it is not going to be installed
Depends: node-which but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
apt-get install npm
deve essere evitato (!). Controlla senpm -v
c'è prima di provare a installare .... (leggi di più sotto alla risposta di @ MarcoCerpi)