c++ - Weird VGL Notice - [VGL] NOTICE: Pixel format of 2D X server does not match pixel format of Pbuffer. Disabling PBO readback -

i'm porting game wrote windows linux. uses glfw , opengl. when run using optirun, take advantage of nvidia optimus setup, spits out console:

[vgl] notice: pixel format of 2d x server not match pixel format of [vgl] pbuffer.  disabling pbo readback. 

i've never seen before, impression i'm loading textures in gl_rgba format, when need in gl_bgra or that. however, i'm using devil's ilutglloadimage function obtain opengl texture handle, never specify format.

has seen before?