node-fs-extra: fs.copy silently fails on windows

This is an upstream issue report from electron-packager#544 and in particular this comment. The issue exists in both 1.0 and 2.0 versions.

electron-packager is a cli helper that packages an electron app. It does so by copying a node app (including node_modules) to the temp directory. This step uses fs.copy which silently fails. Neither the callback is called, nor an error is thrown.

This is the line which fails silently

fs.copy(opts.dir, appPath, {filter: ignore.userIgnoreFilter(opts), dereference: shouldDeref}, cb)

I’d be glad to help you identify root cause of this issue. My current guess that it’s combination of filter/dereference and maybe (?) long paths?

Note that this only happens on windows. On OSX, packaging the project works fine.