node 10 child_process readable

readme.md

readable event called, but calling .read() on the stream results in an empty string.

child_process_test.js

var cp = require('child_process');

var child = cp.spawn('sysevent');

child.stderr.setEncoding('utf8');
child.stderr.on('readable', function () {
    console.log('stderr readable');
    var stderr = '';
    var chunk;
    while ((chunk = child.stderr.read()) !== null)
        stderr += chunk;
    console.dir(stderr);
    console.log('---');
});

child.on('close', function () {});

output.txt

root - build sunos ~/temp # node child_process_test.js 
stderr readable
''
---
stderr readable
'sysevent: sysevent_bind_handle: Bad address\n'
---
stderr readable
''
---