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Make sure you have the latest version of Node

Ensure you have the latest stable version of Node as stated on  

Make sure you have sufficient file privileges

To install Node and StrongLoop , you need permissions to write to directories:

  • /usr/local/bin 
  • /usr/local/lib/node_modules 

If you see errors such as:

npm ERR! Error: EACCES, mkdir '/usr/local/lib/node_modules/strongloop'
npm ERR! Please try running this command again as root/Administrator

Then you don’t have the required rights to create files or directories.  Either change the rights for the specified directories, or run the command using sudo.  In general, it’s better to fix the directory rights as follows:

$ sudo chown -R $USER /usr/local

This command makes your user account the owner of the /usr/local directory. Then you won’t ever have to use sudo to install Node or install packages globally with npm. For more information, see How to Node.

If you have to use sudo, use the following command:

$ sudo npm install -g --unsafe-perm install strongloop

If you have to use sudo, use the following command:

$ sudo npm install -g --unsafe-perm install strongloop

Windows issues

Cygwin not supported

LoopBack does not support Cygwin (Windows bash shell emulator), because Node does not support it for interactive prompts. Use Windows command shell instead.

Xcode license issues

If you see errors such as:

Agreeing to the Xcode/iOS license requires admin privileges, please re-run as root via sudo.

Then you recently upgraded or installed Xcode and haven’t agreed to the license yet. 

Enter the following command to validate your Xcode license, then reinstall StrongLoop:

$ sudo xcode-select

Errors with npm

Peer dependency errors

If you encounter peerDependency conflicts with modules that are already installed globally either through npm install -g or npm link, you may have conflicting versions of modules installed globally. Inspect your global Node module directory (typically /usr/local/lib/node_modules), remove the conflicting modules manually, then re-install.

Firewall issues

A firewall may block npm installation because it blocks git:// URLs.  You can configure Git to use HTTPS instead as follows:

$ git config --global url."https://".insteadOf git://

See Git is blocked, how to install npm modules (StackOverflow) for more details.

Alternatives to public npm registry

Occasionally, the npm package manager will be down or otherwise generate error messages during installation.  When this occurs, you can wait for the npm problem to be resolved, or:

  • Use an alternative registry
  • Install modules from GitHub

 Use alternative registry

In addition to the official npm registry at, there are several alternative npm registries:

To install software from a different registry, use the command:

$ npm —registry <registry_URL> install loopback-cli

Install modules from Github

As a last resort, you can search the name of your package on GitHub and either clone with git clone or download the tarball, unzip and copy it in your node_modules folder.

Errors on Ubuntu

You may see the following errors when installing on Ubuntu:

sqlite3@3.1.1 install /usr/local/lib/node_modules/strong-pm/node_modules/minkelite/node_modules/sqlite3
node-pre-gyp install --fallback-to-build

/usr/bin/env: node: No such file or directory
npm WARN This failure might be due to the use of legacy binary "node"
npm WARN For further explanations, please read
npm ERR! weird error 127
npm ERR! not ok code 0

To fix this, enter the following command:

$ update-alternatives --install /usr/bin/node node /usr/bin/nodejs 99
Tags: installation