Note: As of VMWare Fusion 4.1.2, this hack is no longer necessary. I've left it here mainly for those using older versions of Fusion (though you may not be able to install newer Mountain Lion previews on those older versions of Fusion).
If you're a Mac developer with access to OS X Mountain Lion, you might want to use it in a virtual machine. This is simple in VMware Fusion, but if you try to install VMWare Tools, Mountain Lion will kernel panic. Unfortunately, using virtual OS X without VMware Tools installed is painful—no screen resize, captured and laggy mouse, etc. So here's a workaround to get Mountain Lion working with VMware Tools (this assumes you have Mountain Lion already running in a virtual machine):
- Make a snapshot of your current setup!
- Run the VMWare Tools installer, but do not reboot when it's done. Just leave the installer running onscreen.
- Navigate to /Library > Application Support > VMware Tools.
- Delete vmmemctl.kext and vmmemctl
- Edit (you'll need root power) services.sh in that same directory.
- Comment out these two lines (they're shown commented out, via the # in front of each):12#kextload '/Library/Application Support/VMware Tools/vmmemctl.kext'#'/Library/Application Support/VMware Tools/vmmemctl'
- Save the edited file, quit the editor, and now (via the still-running Installer) reboot the virtual machine.
The initial reboot may take a long time, but it should work. If it doesn't, you're on your own, as I've now exhausted all my knowledge on the topic.