The "find in files" feature needs help. The most glaring problem is that if the "find in files" popup window has the option "recurse in subfolders". If this checkbox is ever unchecked then it will always produce the error:
"/bin/grep: Source Code: Is a directory"
There is no situation when you can do a "find in files" without giving grep the -R command, grep is complaining because geany is passing in an obviously invalid argument. I suggest removing the "recurse in subfolders" entirely or at the very least have it default enabled... (why would want to find in files but not recursively? what tool does that???)
I really would the directory would stay at my project root! Why do you fight with the user over this? Overall geany is awesome but the "find in files" is super annoying. I just end up using grep on the CLI!