I had an issue quite a few time that checkout has been broken (interrupted during update, etc.)
To fix it it's sufficient to do 'svn cleanup'. However subversion-plugin doesn't support it.
In case of a broken checkout poll-scm triggers a new build
but SVN doesn't update this repository:
When I went to the host and than do 'svn up' it complains :
With mentioned 'cleanup' option it would be possible to avoid such a situation. An additional issue is that subversion-plugin doesn't show information about W155037, so build is trigger but without information that repository hasn't been updated.