I serve my Subversion repository from /srv/svn. In the default SELinux targeted policy in Fedora, Apache is not usually allowed to access files here. The following command allows Apache to access my Subversion repo:
# chcon -R -h -t httpd_sys_content_t /srv/svn
This is also needed for trac:
# chcon -R -h -t httpd_sys_content_t /srv/trac