fix: report filename if template file is invalid A file name like .#issue.search.html causes a crash because _find returns None not a tuple and unpacking fails. Trap the TypeError and raise ValueError with message that includes the basename of the file.

try:
    # Python 3+.
    from xmlrpc import client, server
    server.SimpleXMLRPCDispatcher
except (ImportError, AttributeError):
    # Python 2.
    import SimpleXMLRPCServer as server
    import xmlrpclib as client  # noqa: F401