title: Installing Node.js via curl doesn't work
body: <p>I am attempting to follow the instructions here: <a href="https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions" rel="nofollow noreferrer">https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions</a></p>
  
  <p>When I try to install Node.js on my Linux Mint I get the following output I cannot interpret:</p>
  
  <pre><code>daniel@beepboop ~ $ curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash -
  
  ## Installing the NodeSource Node.js 8.x LTS Carbon repo...
  
  
  ## Populating apt-get cache...
  
  + apt-get update
  Ign:1 cdrom://Linux Mint 18.1 _Serena_ - Release amd64 20161213 xenial InRelease
  Ign:2 cdrom://Linux Mint 18.1 _Serena_ - Release amd64 20161213 xenial Release
  ...
  Err:3 cdrom://Linux Mint 18.1 _Serena_ - Release amd64 20161213 xenial/contrib amd64 Packages
    Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
  Ign:4 cdrom://Linux Mint 18.1 _Serena_ - Release amd64 20161213 xenial/contrib i386 Packages
  Hit:48 http://repo.steampowered.com/steam precise InRelease
  Ign:49 http://dl.google.com/linux/chrome/deb stable InRelease                                                                                                                                            
  Hit:50 http://packages.microsoft.com/repos/vscode stable InRelease                                                                                                                                       
  Hit:51 http://dl.google.com/linux/chrome/deb stable Release                                                                                                                                              
  Ign:52 http://packages.linuxmint.com serena InRelease                                                                                                                                                    
  Hit:53 http://archive.canonical.com/ubuntu xenial InRelease                                                                                                                                              
  Hit:54 http://packages.linuxmint.com serena Release                                                                                         
  Get:55 http://repository.spotify.com stable InRelease [3,302 B]                                                                             
  Hit:56 http://ppa.launchpad.net/notepadqq-team/notepadqq/ubuntu xenial InRelease                                                 
  Get:57 http://security.ubuntu.com/ubuntu xenial-security InRelease [107 kB]                    
  Hit:58 http://archive.ubuntu.com/ubuntu xenial InRelease                                                                           
  Get:60 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]                                                              
  Err:55 http://repository.spotify.com stable InRelease                                                                                 
    The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EFDC8610341D9410
  Hit:62 http://ppa.launchpad.net/obsproject/obs-studio/ubuntu xenial InRelease                                           
  Hit:63 http://ppa.launchpad.net/openshot.developers/ppa/ubuntu xenial InRelease                                                                    
  Get:64 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]                                      
  Hit:65 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease
  Fetched 326 kB in 1s (189 kB/s)
  Reading package lists... Done
  W: Target Packages (contrib/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (contrib/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (contrib/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (contrib/i18n/Translation-en_CA) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (contrib/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (main/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (main/i18n/Translation-en_CA) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: The repository 'cdrom://Linux Mint 18.1 _Serena_ - Release amd64 20161213 xenial Release' does not have a Release file.
  N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repository.spotify.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EFDC8610341D9410
  W: Failed to fetch http://repository.spotify.com/dists/stable/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EFDC8610341D9410
  E: Failed to fetch cdrom://Linux Mint 18.1 _Serena_ - Release amd64 20161213/dists/xenial/contrib/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
  W: Some index files failed to download. They have been ignored, or old ones used instead.
  W: Target Packages (contrib/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (contrib/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (contrib/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (contrib/i18n/Translation-en_CA) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (contrib/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (main/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (main/i18n/Translation-en_CA) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:1 and /etc/apt/sources.list.d/sources.list:1
  Error executing command, exiting
  </code></pre>
  
  <p>Have I bricked my OS or something? I cannot find any other examples of this issue.
  Why would packages being configured multiple times make node.js uninstallable? How can I "deconfigure" these packages?</p>
  
  <p>This error doesn't even make it clear that these packages are responsible. Is one in particular responsible, or should I just nuke all of them?</p>
  
  <p>If I try to skip the first line and just install nodejs, I just get nodejs 4.2.6 when I need 8.x.</p>
  
  <pre><code>daniel@beepboop ~ $ sudo apt-get install -y nodejs
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  The following packages were automatically installed and are no longer required:
    gyp libjs-inherits libjs-node-uuid libssl-dev libuv1-dev
  Use 'sudo apt autoremove' to remove them.
  The following NEW packages will be installed:
    nodejs
  0 upgraded, 1 newly installed, 0 to remove and 716 not upgraded.
  Need to get 0 B/3,161 kB of archives.
  After this operation, 13.2 MB of additional disk space will be used.
  Selecting previously unselected package nodejs.
  (Reading database ... 234981 files and directories currently installed.)
  Preparing to unpack .../nodejs_4.2.6~dfsg-1ubuntu4.1_amd64.deb ...
  Unpacking nodejs (4.2.6~dfsg-1ubuntu4.1) ...
  Processing triggers for doc-base (0.10.7) ...
  Processing 1 added doc-base file...
  Registering documents with scrollkeeper...
  Processing triggers for man-db (2.7.5-1) ...
  Setting up nodejs (4.2.6~dfsg-1ubuntu4.1) ...
  update-alternatives: using /usr/bin/nodejs to provide /usr/bin/js (js) in auto mode
  </code></pre>