Hello, Kevjzheng.
In fact, there is something obvious and you are not missing at all. Debugging in Julia is some awful experience for a lot of people. So I’m really sorry if my response doesn’t give you a solution. I’m going to put here posts about debugging in julia so you can see that is a very hot topic and people coming from other languages that are used to debug are facing the same issue. In the first post you can find a discussion about some debugger Pkg