An awesome jamming crack line, hidden in plain sight under the block behind La Memel. This on is slightly easier if you are small, because the exit is a bit tight.
Rain sucks, but broken holds suck even more. Remember, never climb on wet rock in Fontainebleau.
The sandstone becomes brittle, and pulling on it will ruin classic problems. Drying it doesn't help, because it's still wet and weak inside.
All you can do is wait for better conditions.