Set the error for the handler. This lets the operation fail with the provided error. You may only set the error once.
src
must be non-%NULL.
Note that src
is no longer valid after this call. If you want
to keep using the same GError*, you need to set it to %NULL
after calling this function on it.
Opaque type with parameters for the callback. The actual content depends on the %NMKeyfileHandlerType.