I am affected by the same bug since I recently upgraded from Debian Jessie to Stretch. Bumblebee worked previously. Now I get this problem, both on nouveau and on non free nvidia drivers.
Here are my logs: [nohus] nohus:(~)❯❯❯ optirun -vv --debug glxgears [ 3527.143580] [DEBUG]Reading file: /etc/bumblebee/bumblebee.conf [ 3527.143825] [DEBUG]optirun version 3.2.1 starting... [ 3527.143837] [DEBUG]Active configuration: [ 3527.143844] [DEBUG] bumblebeed config file: /etc/bumblebee/bumblebee.conf [ 3527.143851] [DEBUG] X display: :8 [ 3527.143858] [DEBUG] LD_LIBRARY_PATH: [ 3527.143865] [DEBUG] Socket path: /var/run/bumblebee.socket [ 3527.143872] [DEBUG] Accel/display bridge: auto [ 3527.143878] [DEBUG] VGL Compression: proxy [ 3527.143886] [DEBUG] VGLrun extra options: [ 3527.143893] [DEBUG] Primus LD Path: /usr/lib/x86_64-linux-gnu/primus:/usr/lib/i386-linux-gnu/primus:/usr/lib/primus:/usr/lib32/primus [ 3527.594436] [DEBUG]Using auto-detected bridge virtualgl [ 3528.051511] [INFO]Response: No - error: [XORG] (EE) [ 3528.051551] [ERROR]Cannot access secondary GPU - error: [XORG] (EE) [ 3528.051558] [DEBUG]Socket closed. [ 3528.051573] [ERROR]Aborting because fallback start is disabled. [ 3528.051579] [DEBUG]Killing all remaining processes. In journalctl when running optirun: Dec 31 15:53:14 nohus bumblebeed[719]: [ 4023.682085] [ERROR][XORG] (EE) Dec 31 15:53:14 nohus bumblebeed[719]: [ 4023.682109] [ERROR][XORG] (EE) Dec 31 15:53:14 nohus bumblebeed[719]: [ 4023.682116] [ERROR][XORG] (EE) Dec 31 15:53:14 nohus bumblebeed[719]: [ 4023.682121] [ERROR][XORG] (EE) Dec 31 15:53:14 nohus bumblebeed[719]: [ 4023.682127] [ERROR][XORG] (EE) Dec 31 15:53:14 nohus bumblebeed[719]: [ 4023.682133] [ERROR]X did not start properly Also, the GPU stays ON as reported by /proc/acpi/bbswitch after trying to run optirun, until turned OFF manually with "rmmod nouveau; tee /proc/acpi/bbswitch <<< OFF"
