Ruby: Too many open files @ rb_sysopen

• EMFILE is too many files opened in your process.
• ENFILE is too many files opened in the entire system.

So Errno::EMFILE is due to the ruby process opening too many files. This limit is probably set to the default 1024 can be seen with:

$ulimit -n
1024

Instead of:

$ulimit
unlimited

You can raise the limit using this method.