nant-cvs-2007-6-23 build error (in mono-svn-106380)_

mkdir -p bootstrap
cp -R lib/ bootstrap/lib
# Mono loads log4net before privatebinpath is set-up, so we need this in the same directory
# as NAnt.exe
cp lib/common/neutral/log4net.dll bootstrap
cp src/NAnt.Console/App.config bootstrap/NAnt.exe.config
mono bootstrap/NAnt.exe -f:NAnt.build build

BUILD FAILED

Exception has been thrown by the target of an invocation.

This .resources file requires unsupported set class version: 2

For more information regarding the cause of the build failure, run the build again in debug mode.

Try 'nant -help' for more information