I'm not using maven or anything, just plain Intellij.
I've opened a binary jar and it had the "Attach sources" link. I selected a jar file and attached it. After opening the source, I realized I have attached the wrong jar file.
However IntelliJ doesn't seem to allow me to change it. There are no options in the GUI. I've manually changed the project files from Notepad and it still keeps opening the wrong file. Why am I as a user being punished so much for one tiny mistake? Why is there no Source > Attach different source... menu?
I had to delete the project and recreate it from scratch to make it work.