What does this mean: considerRebuildOfPrelinkedKernel prebuild rebuild has expired

Question

A line I accidentally spotted in system.log on MacOS X 10.9.1 when I connected an external USB webcam for the first time ever.... Subsequent connects to the usb port did not produce this message again. So it may not even be related. Except for Safari nothing else was running at that time.

Basically I'm asking purely out of curiosity I'm aware that most probably I can just ignore this.

Screenshot:

Solution

It means that there is not a driver for that device in the kernel. Since Mac OSX uses a microkernel vs monolithic kernel like Linux. If you need to install drivers for this, an easy way to figure out what you need is to use a linux system. On the Linux machine, as root, run dmesg, then plug the device in and run dmesg again. Linux should tell you what the chipset is. Use this information in your search for a Mac OSX driver.

Now for your specific case, it is possible that upon insertion something went wrong with the USB interface and it could not recognize the device and map it to the right driver. The next time you plugged it in, everything was working as you would expect.