I noticed the current handling of broken svn:externals in the hudson subversion plugin is wrong.

this is the behaviour of a checkout with a valid svn:externals property:
Build #1 (02-May-2010 07:18:20)
add description Revisions
https://localhost/svn/test/wibble : 135
https://localhost/svn/test : 136
No changes.

Console Output
Started by user admin
Checking out https://localhost/svn/test
A bar
A bar/hello.txt
A wibble
A wibble/bye.txt
Fetching 'https://localhost/svn/test/wibble' at -1 into '/home/hudson/jobs/test/workspace/test/bar/wibble'
A bar/wibble/bye.txt
At revision 136
At revision 136

now I break the svn:externals property committing an invalid path:
Build #2 (02-May-2010 07:21:27)
add description Revision: 137
Changes
breaking the path of the svn external (detail)

Console Output
Started by user admin
Checking out https://localhost/svn/digitalgold/test
A bar
A bar/hello.txt
A wibble
A wibble/bye.txt
At revision 137

As it can be seen there's no mention of any error during the checkout stage. When using the svn command at least there is a warning:
svn co https://localhost/svn/test
A test/bar
A test/bar/hello.txt
A test/wibble
A test/wibble/bye.txt
svn: warning: Error handling externals definition for 'test/bar/wibble':
svn: warning: URL 'https://localhost/svn/test/wibble-broken' at revision 137 doesn't exist
Checked out revision 137.

I also wonder if it would be useful to provide an option in the Source Code Management Subversion section to fail the build immediately if there is an issue handling svn:externals definitions like in the case above.

many thanks.