Today (10/09/2008) I ran into a weird bug with Eclipse 3.3.x. The other day, I had to remove my internal hard-drive because I was sending the laptop in for repair. I used an external exclosure to turn the internal hard-drive into an external hard-drive and plugged it into the USB port on my personal laptop. The external drive came up as the E:\ drive. Anyway, long-story-short I was abe to use my Eclipse workspace on the external drive with my personal laptop for a few days. I had to switch some Eclipse settings (i.e. ANT HOME) in order to compile code. When I switched back to using the drive in my laptop (yesterday), I kept getting the following error message.
Buildfile: C:\Documents and Settings\Justin Miranda\My Documents\My Workspace\LogicRestModule\build.xml
[javac] Compiling 5 source files to C:\Documents and Settings\Justin Miranda\My Documents\My Workspace\LogicRestModule\build
C:\Documents and Settings\Justin Miranda\My Documents\My Workspace\LogicRestModule\build.xml:42: Error starting modern compiler
After playing around with the Java Compiler and Ant settings and restarting Eclipse a few times, nothing seemed to be helping. I downloaded the latest version of the code I was trying to compile and was able to successfully compile that code. But on restart, an attempt to "ant clean", then "ant package-module" caused the same error.
Then I remembered a nice little trick: Eclipse Clean. For some reason that worked.