Sometimes you can't attach a debugger at all! I've dealt with plenty of things that will do some strange kind of fork/exec magic and shed all the debug information in the process.

And other things that will only show some small useless snippets of the stack. You pass a bunch of parameters to tell it to show more, but then invariably you find the code is using a custom logger that's cutting the thing off or some part of a library resets all your settings or the forked processes don't inherit everything, it almost never just does what you tell it to, there's something else in there ignoring it.

I wish I could have the opportunity to even get to that problem half the time