[ESS] debugging, mostly tracebug

[Ross Boylan]

I just tried ess-tracebug with ESS 12.09-1.

I had hoped that the package would let me position breakpoints on the 
fly, but it seems not to work that way.  Instead you insert breakpoints 
into a source file and then read it in.  This means you can not set a 
breakpoint at a new location while in a debugging session, and also that 
you must clear the breakpoints before "really" saving the file (e.g., a 
VCS commit).  Is my understanding correct, or is there a better way?

Is the enable/disable breakpoints a half way house, so that one can 
enable and disable on the fly, or does that require rereading the source 
too?

I followed the instructions at http://code.google.com/p/ess-tracebug/, 
hoping that it would magically realize that the code I was fiddling with 
was in a package/namespace.  Seemingly it did not.

Vitalie Spinu previously ("developing packages with namespaces" around 
Feb 6) recommended using ess-developer, and Barry Rowlingson suggested 
devtools.  Can either of those be combined with ess-tracebug?

I'm  not sure how R got this far with such minimal debugging 
facilities.  As far as I know, one can't step into a function (without 
first saying debug(function), which is permanent), can't step n steps 
forward, and can't add and remove breakpoints on the fly.  Or am I 
missing something?

Ross Boylan