Attaching file with HTML5 filesystem API does not work.

[franza]

I have a BB10 app that produces a log file. Log file was created with blackberry.io.sandbox = false so it should be somewhere in the app data. To attach this file to the email I'm doing next thing:

var filepath = Logger.logFileEntry.fullPath; //Logger.logFileEntry is FileEntry
//filepath is something like "/accounts/1000/appdata/APP_NAME.testDev_ackBerry_107e9d1c19/data/logs/2013-07-18 20:04:36.log"

blackberry.invoke.card.invokeEmailComposer({
    subject: "Email subject",
    body: "Email body",
    to: ["my@mail.com"],
    attachment: [filepath]
});

This code opens an email app with an entry in attachments. But attachment has 0 bytes size and when I send this email I receive no attachments.