npm throws an error on master #1898

$ npm
module.js:334
    throw err;
          ^
Error: Cannot find module 'internal/smalloc'
    at Function.Module._resolveFilename (module.js:332:15)
    at Function.Module._load (module.js:282:25)
    at Module.require (module.js:361:17)
    at require (module.js:380:17)
    at evalmachine.<anonymous>:22:20
    at Object.<anonymous> (/usr/local/lib/node_modules/npm/node_modules/graceful-fs/fs.js:11:1)
    at Module._compile (module.js:426:26)
    at Object.Module._extensions..js (module.js:444:10)
    at Module.load (module.js:351:32)
    at Function.Module._load (module.js:306:12)