Comment 40 for bug 1310023

Using Ubuntu 14.04, intel hd 3000, nvidia gt540m, same problem as above unable to switch from intel to nvidia, updated system still same bug,

sudo prime-select query
unknown

sudo prime-select nvidia
Error: alternatives are not set up properly
Error: nvidia mode can't be enabled

sudo cat /proc/acpi/bbswitch
0000:01:00.0 ON

dmesg | grep -E 'bbswitch|nvidia'
[ 9.854343] bbswitch: module verification failed: signature and/or required key missing - tainting kernel
[ 9.854498] bbswitch: version 0.7
[ 9.854504] bbswitch: Found integrated VGA device 0000:00:02.0: \_SB_.PCI0.GFX0
[ 9.854510] bbswitch: Found discrete VGA device 0000:01:00.0: \_SB_.PCI0.PEG0.PEGP
[ 9.854565] bbswitch: detected an Optimus _DSM function
[ 9.854574] bbswitch: Succesfully loaded. Discrete card 0000:01:00.0 is on
[ 22.177483] init: Failed to spawn nvidia-persistenced main process: unable to execute: No such file or directory