I used to have my laptop connect to an external monitor using the "intel-virtual-output." However, I had some technical issues with bumblebee that had to reinstall the Mesa drivers. Now I can't get the second display to work. When I try to connect the second monitor, I get the following response:
intel-virtual-output -f
No VIRTUAL outputs on ":1".
Some information on my system:
lspci -nnk | egrep 'VGA|3D' -A3
00:02.0 VGA compatible controller [0300]: Intel Corporation HD Graphics 630 [8086:591b] (rev 04)
    Subsystem: Acer Incorporated [ALI] Device [1025:118a]
    Kernel driver in use: i915
    Kernel modules: i915
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GP107M [GeForce GTX 1050 Mobile] [10de:1c8d] (rev a1)
    Subsystem: Acer Incorporated [ALI] Device [1025:118b]
    Kernel driver in use: nvidia
    Kernel modules: nouveau, nvidia_drm, nvidia
lsmod | grep nvidia
nvidia_uvm            901120  0
nvidia_drm             49152  2
nvidia_modeset       1097728  1 nvidia_drm
nvidia              18239488  2 nvidia_modeset,nvidia_uvm
drm_kms_helper        204800  2 i915,nvidia_drm
drm                   491520  13 i915,nvidia_drm,drm_kms_helper
ipmi_msghandler        65536  2 nvidia,ipmi_devintf
xrandr  --listproviders
Providers: number : 1
Provider 0: id: 0x43; cap: 0xf (Source Output, Sink Output, Source Offload, Sink Offload); crtcs: 3; outputs: 1; associated providers: 0; name: modesetting
    output eDP-1
xrandr --listmonitors
Monitors: 1
 0: +*eDP-1 1920/344x1080/193+0+0  eDP-1
Your help on this matter is greatly appreciated.