gistfile1.txt

 jspm install aurelia-validation
     Updating registry cache...
     Looking up github:aurelia/validation
     Looking up github:aurelia/templating
     Looking up github:aurelia/binding
     Looking up github:aurelia/dependency-injection
     Looking up npm:core-js
     Downloading npm:core-js@0.9.6
     Looking up github:aurelia/loader
     Looking up github:aurelia/html-template-element
     Looking up github:aurelia/metadata
     Looking up github:aurelia/logging
     Looking up github:aurelia/path
     Looking up github:aurelia/task-queue
     Looking up github:webcomponents/webcomponentsjs

warn Error on lookup for github:webcomponents/webcomponentsjs, retrying (1).
     Error: spawn EMFILE
         at errnoException (child_process.js:1011:11)
         at ChildProcess.spawn (child_process.js:958:11)
         at exports.spawn (child_process.js:746:9)
         at Object.exports.execFile (child_process.js:628:15)
         at exports.exec (child_process.js:591:18)
         at /usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:288:7
         at lib$rsvp$$internal$$initializePromise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:537:9)
         at new lib$rsvp$promise$$Promise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:850:9)
         at GithubLocation.lookup (/usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:287:12)
         at Promise.resolve.then.then.active (/usr/local/lib/node_modules/jspm/lib/registry.js:134:30)

warn Error on lookup for github:webcomponents/webcomponentsjs, retrying (2).
     Error: spawn EMFILE
         at errnoException (child_process.js:1011:11)
         at ChildProcess.spawn (child_process.js:958:11)
         at exports.spawn (child_process.js:746:9)
         at Object.exports.execFile (child_process.js:628:15)
         at exports.exec (child_process.js:591:18)
         at /usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:288:7
         at lib$rsvp$$internal$$initializePromise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:537:9)
         at new lib$rsvp$promise$$Promise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:850:9)
         at GithubLocation.lookup (/usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:287:12)
         at Promise.resolve.then.then.active (/usr/local/lib/node_modules/jspm/lib/registry.js:134:30)

warn Error on lookup for github:webcomponents/webcomponentsjs, retrying (3).
     Error: spawn EMFILE
         at errnoException (child_process.js:1011:11)
         at ChildProcess.spawn (child_process.js:958:11)
         at exports.spawn (child_process.js:746:9)
         at Object.exports.execFile (child_process.js:628:15)
         at exports.exec (child_process.js:591:18)
         at /usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:288:7
         at lib$rsvp$$internal$$initializePromise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:537:9)
         at new lib$rsvp$promise$$Promise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:850:9)
         at GithubLocation.lookup (/usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:287:12)
         at Promise.resolve.then.then.active (/usr/local/lib/node_modules/jspm/lib/registry.js:134:30)

warn Error on lookup for github:webcomponents/webcomponentsjs
     Error: spawn EMFILE
         at errnoException (child_process.js:1011:11)
         at ChildProcess.spawn (child_process.js:958:11)
         at exports.spawn (child_process.js:746:9)
         at Object.exports.execFile (child_process.js:628:15)
         at exports.exec (child_process.js:591:18)
         at /usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:288:7
         at lib$rsvp$$internal$$initializePromise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:537:9)
         at new lib$rsvp$promise$$Promise (/usr/local/lib/node_modules/jspm/node_modules/rsvp/dist/rsvp.js:850:9)
         at GithubLocation.lookup (/usr/local/lib/node_modules/jspm/node_modules/jspm-github/github.js:287:12)
         at Promise.resolve.then.then.active (/usr/local/lib/node_modules/jspm/lib/registry.js:134:30)

err  Error looking up github:webcomponents/webcomponentsjs.

warn Installation changes not saved.

As CharlesPockert suggested check your ulimit -a and increase number of opened files for example to: ulimit -S -n 2048