I rely on lldb to fine-tune and study my code optimizations as an applied math instructor, and somehow, probably upgrading either macOS to 10.13.6, or the last compiler suite from Apple for that version of the OS broke lldb. Here is a short fragment. The compiled C object, julian, is unimportant in itself as lldb behaves the same way with every C program I have every written on this machine. I can’t say when lldb actually broke as it has been some time since I needed to use lldb. The last time I used it, it worked perfectly, as I have many C programs that were tested when written with lldb. Recompiling the programs does not resolve the problem. Also, reinstalling Apple’s command line tools fails to fix the problem, nor does compiling with alternate front ends.