Thanks for sharing that. I have similar experiences that saved myself (more than once) by patching 3rd party libraries. In our case, they were proprietary and

Thanks for sharing that. I have similar experiences that saved myself (more than once) by patching 3rd party libraries. In our case, they were proprietary and we didn't have the source. Sometime it was an apparent bug in the library, sometimes it was that the library functionality came short to cover the cases we wanted to handle. Inspecting their library internals with "apropos", "describe" and other means, and defining "around" method on their internal generic functions, we could just inject our fix or enhancement to the libraries. I admit it was nasty; however, if it weren't Lisp, we had to file a bug report or a feature request to the vendor and wait for them, or to find alternative libraries, or to reimplement things by ourselves. (Open source advocates may say it was our fault to use proprietary library, but proprietary libraries exist for reason; besides, inspecting and modifying things without recompiling the entire library is very useful even you have the source.) Such emergency patching is like a safety net. In the end you may not have needed it if everything goes smoothly as planned, but it is good to know it exists, and even good if it saves you from disaster.