jQuerytools build error

gistfile1.js

    minifying v1.2.0:src/tooltip/tooltip.slide.js
    minifying v1.2.0:src/tooltip/tooltip.js
    minifying v1.2.0:src/tooltip/tooltip.dynamic.js
    minifying v1.2.0:src/toolbox/toolbox.mousewheel.js
    minifying v1.2.0:src/toolbox/toolbox.history.js
    minifying v1.2.0:src/toolbox/toolbox.flashembed.js

    ...
    ...

    minifying v1.2.3:src/scrollable/scrollable.autoscroll.js
    minifying v1.2.3:src/dateinput/dateinput.js
    minifying v1.2.3:src/overlay/overlay.apple.js
    minifying v1.2.3:src/rangeinput/rangeinput.js
    pipe(): Too many open files

    node.js:134
            throw e; // process.nextTick error, or 'error' event on first tick
            ^
    Error: Error spawning
        at ChildProcess.spawn (child_process.js:243:28)
        at Object.spawn (child_process.js:31:15)
        at Object.cmd (/Users/bradrobertson/git/javascript/jquerytools-builder/lib/git.js:22:31)
        at Object.show (/Users/bradrobertson/git/javascript/jquerytools-builder/lib/git.js:123:13)
        at /Users/bradrobertson/git/javascript/jquerytools-builder/lib/git.js:147:21
        at /Users/bradrobertson/git/javascript/jquerytools-builder/deps/async/lib/async.js:74:13
        at Array.forEach (native)
        at /Users/bradrobertson/git/javascript/jquerytools-builder/deps/async/lib/async.js:20:36
        at Object.forEach (/Users/bradrobertson/git/javascript/jquerytools-builder/deps/async/lib/async.js:73:9)
        at /Users/bradrobertson/git/javascript/jquerytools-builder/lib/git.js:146:15