Package dependencies

[ldecicco-USGS]

Sorry if this is answered somewhere else, I searched but maybe missed it. Can drake track R package versions? IE...could I pass my drake workflow to a collaborator and somehow easily have them run a function that would check for the existence of all the required packages? (and install? update or revert to an older version?)

Maybe another way to ask...does drake managed and save "project metadata" like the package versions and where they came from (ie..github/CRAN/etc). This would go a long way in reproduciblity.

[wlandau]

For metadata, drake does save the sessionInfo() of the last make(), and you can retrieve it from the cache using drake_session(). Package management in general is unfortunately beyond the scope of drake. There was a discussion in #6 (deeply buried, I know), but diving into package dependencies seemed to just make pipelines more brittle (prone to triggering updates), and drake already tries to do a lot as it is. I ended up deciding to promote packrat and containerization (Docker or Singularity) instead.