Thanks a lot for the comments! Pauan's right that the indent sensitivity seems to require the two newlines, and it is indeed weird that responses get grouped with the next command. I'm still looking for a better approach.
I'm interested in that warning you get. Are you on a 64-bit system? Could you type in the following into gdb and share the results?
$ gdb -q
(gdb) p sizeof(int)
(gdb) p sizeof(long)
(gdb) p sizeof(void*)
Edit: I just noticed that gdb on my machine gives different results with and without a binary. So you'll need to invoke it from the wart directory like so:
Also, it seems that error message came up only the first time I ran wart. I haven't seen it in later executions so there's probably no need for any additional concern. :)
It comes up when building the C files. Since you haven't made any changes to the sources since there's no need to rebuild. But you can see it again if you first run: