MDS Error: /var/folders/lM
From Apple Support Communities, with some correction:


Command-S at startup for Single User Mode
Repair the files ystem as indicated on screen using fsck (took three runs)
Mount the file system as indicated on screen, /sbin/mount -uw /
Go to /Library/Caches and do rm -rf *
Go to my home folder /Users/.../Library/Caches and do rm -rf *
Remove a Spotlight folder, rm -rf /.Spotlight-V100
Go to /var/folders and do rm -rf *
Start normally using exit or reboot command as indicated on screen


Be extremely careful with the rm -rf commands! To double-check that you're in the correct directory: 

pwd


I hope that helps!