Bug#963980: bumblebee-nvidia: Bumblebee daemon reported: error: [XORG] (EE) Unable to locate/open config directory

[Vincas Dargis]

$ sudo strace -efile -f -p $(pgrep bumblebeed) 2>&1 | fgrep /etc/bumblebee
[pid  7068] execve("/usr/lib/xorg/Xorg", ["/usr/lib/xorg/Xorg", ":8", "-config", 
"/etc/bumblebee/xorg.conf.nouveau", "-configdir", "/etc/bumblebee/xorg.conf.d", "-sharevts", 
"-nolisten", "tcp", "-noreset", "-verbose", "3", "-isolateDevice", "PCI:01:00:0"], 0x7fff6ca8f198 /* 
4 vars */ <unfinished ...>
[pid  7068] openat(AT_FDCWD, "/etc/bumblebee/xorg.conf.d", 
O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 16
[pid  7068] openat(AT_FDCWD, "/etc/bumblebee/xorg.conf.nouveau", O_RDONLY) = 16