I would love to post a comprehensive list of gotchas, but then that would make them not gotchas if you know what I mean as I would know them all. So instead, I will mention what sidelined me for several hours last night and hope to spur some discussion about what other people have come across. If I think of others over time, I will try to update this post.
Space after the function name. I had copied and pasted some functions from somewhere else in my client's repository and the functions had no space between the name and the opening parenthesis of the passed variable declarations. I was not (and I guess still am not) aware of a limitation in this regard, but I saw all sorts of strange behavior afterward. Namely, the calls to these functions seemed to be ignored which took me a long time to realize. They seem to work fine in their original home elsewhere in the repository so this may be related to context, but suffice to say this is some thing to think about when troubleshooting.
