"toString()" failed when running machine-export

[rymir]

osx: 10.11.6
node: v7.4.0
npm: 4.1.1
machine-share: 0.1.1

When running machine-export test, I keep getting:

exporting.
buffer.js:503
    throw new Error('"toString()" failed');
    ^

Error: "toString()" failed
    at Buffer.toString (buffer.js:503:11)
    at Walker.<anonymous> (/usr/local/lib/node_modules/machine-share/export.js:62:85)
    at emitThree (events.js:116:13)
    at Walker.emit (events.js:194:7)
    at Object.emitSingleEvents [as emitNodeType] (/usr/local/lib/node_modules/machine-share/node_modules/walk/lib/node-type-emitter.js:55:13)
    at Walker._wLstatHandler (/usr/local/lib/node_modules/machine-share/node_modules/walk/lib/walk.js:87:19)
    at /usr/local/lib/node_modules/machine-share/node_modules/walk/lib/walk.js:105:12
    at FSReqWrap.oncomplete (fs.js:112:15)
make: *** [export] Error 1

doing something wrong?