I wonder what it would take to bring Linux to this state, where while running a program, you can decide to look at the source code, check in the debugger what i

I wonder what it would take to bring Linux to this state, where while running a program, you can decide to look at the source code, check in the debugger what is going on, apply a change and run the program as if you used the precompiled version of it with very little effort. So you could make changes to programs with similar manual effort as if you changed a config file. And when updating the programs, the package manager would check for your manual changes, if they can be applied without merge conflicts. Upstreaming the changes would also be a simple standardized command. But you wouldn't have to, just to be able to run the changed software without friction.