Misealding Error message "The scm url cannot be null"

Actually, what is looked-for in the code is <scm><developerConnection> which is confusing, since <scm><url> exists (but has nothing to do) and we migth think that <scm> <connection> is largely enough to check the working copy for modification.

Moreover, looking at mailinglists on google, I found quite some people stuck with this very error message and no clue of what's happening.