As of SourceForge 4.3 SP1, you can use Velocity to customize the pages of SourceForge and make the version comment required. Simply create /usr/local/sourceforge/sourceforge_home/templates/body_footer.vm with the contents below.
<script> var updateButton = document.getElementById('edit_wiki_page.update'); if ( updateButton ) { updateButton.href = 'javascript:submitWikiPageUpdate();'; } function submitWikiPageUpdate () { if ( document.editPage.versionComment.value ) { submitForm(document.editPage, 'submit'); return; } alert("Please include a detailed Version Comment for this change."); } </script>
Then, make sure the file is owned by the sf-admin user:
chown -R sf-admin.sf-admin /usr/local/sourceforge/sourceforge_home/templates
And ensure proper permissions:
chmod 0644 /usr/local/sourceforge/sourceforge_home/templates/body_footer.vm
SourceForge picks up the change immediately.