The most annoying subversion error message:

$ svn up
...
svn: Won't delete locally modified directory 'foo/bar'
svn: Left locally modified or unversioned files

This happens when a subdirectory of 'foo/bar' is removed from the upstream repository, and subversion tries and fails to remove ir locally -- fails because it finds some some files that are listed in svn:ignore (e.g. editor backup files, compiled object files, compiled Python modules).

Now you have to figure out which subdirectory of 'foo/bar' subversion wants to remove. Then you have to manually remove junk files from it. Then you have to repeatedly try various combinations of svn up and svn cleanup until Subversion finally agrees to continue the interrupted svn up operation.

Please, Subversion folks -- if you cannot delete a directory because it contains just junk files (those ignored in the output of svn status), just print a meaningful warning message (and name the correct directory rather than its parent!) and continue with the update.

Debian bug 246131.

Update: It seems to be fixed in Subversion 1.1. Unfortunately Subversion 1.1 is not in Debian.