On the libsvn wiki page, the downloads for svn bindings are for SVN 1.7.5. If used with hgsubversion to clone a repository created with SVN 1.9 or greater, user will encounter an error similar to the following:
hg clone 'file:///C:/svn_repo'
destination directory: trunk
abort: Unable to open an ra_local session to URL
Unable to open repository 'file:///C:/svn_repo'
'C:\svn_repo\db\format' contains invalid filesystem format option 'addressing logical'
For SVN repos created with SVN 1.9 using FSFS format 7, older versions of SVN can't access the repo as has been documented several times (http://stackoverflow.com/a/33264998)
Suggest adding subversion bindings for python for the newest version of SVN to the downloads section as downgrading the version of used to create a repository isn't possible in some situations.