When hudson is constructing the path to the workspace checkout location for an
svn external, it includes an extra slash in the path. For example:

ERROR: Failed to parse svn info for external
http://10.1.42.211/svn/textura/lib/j4j/1.0 at
portal/home/tomcat/hudson/workspace/portal/lib//j4j

Note the lib//j4j at the end of the previous line.