Solution for: #99: Trac reports "Insufficient permissions" when using fine-grained permissions

In trac.ini, look for the [trac] section, then set:
authz_file = [path to svn-access] authz_module_name = [repository name or prefix] #...skipped.. permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy

Most importantly, you should not forget to set authz_module_name if you used a repository name in svn-access. For example, if your svn-access file looked like:
[vault1:/foo] yliu = rw

then authz_module_name for vault1's corresponding trac.ini should be set to vault1.