Unison Aborted

I use the Unison file synchronizer extensively.  I was very disappointed when I was recently trying to copy a directory structure I copied from a cd lately.  I ran unison, and it failed with the sole message "Aborted".  No file or directory name, no hint to the problem.  After much frustration, I finally found the problem.  The Windows machine that made the cd had for some reason created a bunch of files beginning with a ".".  (perhaps for indexing purposes?)  After deleting these files with

find . -name "\.*" -exec rm -f {} \;    

Unison worked correctly.  Why couldn't they issue a reasonable error message?

Update:

Turns out those '.' files were "Resource forks", a Mac HFS relic.   If you
add "rsrc = false" to the profile, it will ignore the offending files.