xml diff files not being produced

Applied the git snapshot moodle-r2-6ec920e17ed6ebf3d9b8737e3a8aadad996fc97d.tar.gz. It's still the latest as I write. Got the error below. Neither xml.dif files are being produced. I get an error when running from command line that the xml diff can't be found. Tried on two different courses. Both have same problem. Probably something simple. May be something on my build.

"C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/xdelta/xdelta3.exe" -d -s "C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/moodledata/temp/a7a9aff7b5ca8b9bd7df7cf2f191fa3d-48496075ea2e4/moodle.xml" "C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/moodledata/temp/1e03842372af8fb727073f687627ad88/files/moodle.xml.diff" "C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/moodledata/temp/a7a9aff7b5ca8b9bd7df7cf2f191fa3d-48496075ea2e4/moodle.xml.undiff"

• line 237 of lib\xdelta.class.php: call to debugging()
• line 169 of backup\incremental_backuplib.php: call to xdelta->apply_diff()
• line 245 of backup\incremental_backuplib.php: call to apply_incremental()
• line 69 of backup\get_incremental.php: call to download_incremental()

C:\projects\VLE\Mobile Moodle\environments\xampplite-win32-1.6.6.exe\development\offlinemoodle-0.4\htdocs\moodle\backup>"C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/xdelta/xdelta3.exe" -d -s "C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/moodledata/temp/a7a9aff7b5ca8b9bd7df7cf2f191fa3d-48496075ea2e4/moodle.xml" "C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/moodledata/temp/1e03842372af8fb727073f687627ad88/files/moodle.xml.diff" "C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/moodledata/temp/a7a9aff7b5ca8b9bd7df7cf2f191fa3d-48496075ea2e4/moodle.xml.undiff" C:\projects\VLE\Mobile Moodle\environments\xampplite-win32-1.6.6.exe\development\offlinemoodle-0.4\htdocs\moodle\lib\xdelta.class.php: apply_diff (252): $basepath = C:/projects/VLE/Mobile Moodle/environments/xampplite-win32-1.6.6.exe/development/offlinemoodle-0.4/moodledata/temp/a7a9aff7b5ca8b9bd7df7cf2f191fa3d-48496075ea2e4
C:\projects\VLE\Mobile Moodle\environments\xampplite-win32-1.6.6.exe\development\offlinemoodle-0.4\htdocs\moodle\lib\xdelta.class.php: apply_diff (253): $different = /moodle.xml

Warning: rename(/moodle.xml.undiff,/moodle.xml) [function.rename]: No such file or directory in C:\projects\VLE\Mobile Moodle\environments\xampplite-win32-1.6.6.exe\development\offlinemoodle-0.4\htdocs\moodle\lib\xdelta.class.php on line 254