Any time I'm seeing really strange results involving the terminal, I try to look for terminal-related weirdness. There is a lot of stuff going on that people generally ignore or simply don't know about, because it generally just works.

And when it doesn't, if you're not at least a little familiar with what's going on, it can be a deeply confusing and obscure little world.

I don't know if it's still valid, but SBCL has a readme entry indicating that building in xterm is much faster than building in gnome-terminal. SBCL's build output is incredibly noisy and the compiler is quite fast, so the combination of the two makes for an incredible rater of output to the terminal.

I remember how confusing IO was in college. Even the implicit flush requirement to show stuff. Utter dread. Few years ago I read an old lisp book (something written before Common Lisp), they don't touch IO until the end, for transparency/bootstraping reasons, and since it's insignificant for thinking it's a straightforward model without fancy features, I wish people taught CS this way.