Your /etc/profile might have a line like this:

# No core files by default
ulimit -S -c 0 > /dev/null 2>&1

‘-c 0′ means that core file are to be of size 0. that is, there will be no core files.

This can be fixed by typing:

$ulimit -c unlimited

Note that this fix only works for the terminal that line is typed in.

If the fd member of a struct pollfd in the array passed to poll() is set to −1, it will be ignored.