[JackeJR]

browser() ?

[disgruntledphd2]

trace subsumes browser, it's much more flexible and can be applied to library code without editing it.

[wdkrnls]

Is there a way to trace an attribute to a function? I couldn't find one, but curious if it exists. I seemed blocked by the fact that trace seemed to expect a name as a character string. Some functions in base R have functions in their attributes which modify their behavior (e.g. selfStart). I ended up just copying the whole code locally and then naming it, but for a better interactive experience I really wish there was a way to pass a function object as I can with debug.

[tylermw]

trace is great for shimming in your own code to an existing function, but it’s not an interactive debugging tool.

[disgruntledphd2]

It sure is. If you set the second argument to browser you can step through any function.