Debugger line stepping very slow

[wrh]

I'm a new user to Code:Blocks, using v. 16.01 with clang C++, on an Ubuntu system running on System 76 hardware
(Ubuntu: 16.04 LTS. "Intel® Core™ i7-7700 CPU @ 3.60GHz × 8", "31.4 GiB").
Line stepping in the debugger is very slow, typically taking 5 seconds to advance from one line to the next.
I've found some matches on similar problems, but none seem exactly applicable to my situation.
I can not find a current bug report.  Is this a known problem?  Are there any workarounds,
e.g. disabling some debugger features?  Does it warrant a bug report?

[BlueHazzard]

Can you reproduce the slowly-ness also when you use the command line gdb to debug, or only in codeblocks?

[oBFusCATed]

Do you have locals/function arguments enabled? Do you have big arrays/vectors in scope? Do you watch big arrays?