Rstudio Clean and Rebuild lazy data error - r

Question

I am trying to develop a R package with RStudio. Lately, I have had no success.
devtools::build(), devtools::reload() and devtools::check() give:
Updating CF documentation
Loading CF
Error in aes(x = gdpPercap, y = lifeExp, size = pop, color = continent, (from mapping.R#1) :
could not find function "aes" or the data.
devtools::check() gives other information, which I list below.
Clean and Rebuild gives:
1] "/Users/PJO/Desktop/CF_0.1.0.tar.gz"
==> R CMD INSTALL --preclean --no-multiarch --with-keep.source CF.2.24
installing to library ‘/Users/PJO/Library/R/3.4/library’
installing source package ‘CF’ ...
** R
** data
*** moving datasets to lazyload DB
** inst
** preparing package for lazy loading
Error in aes(x = gdpPercap, y = lifeExp, size = pop, color = continent, :
could not find function "aes"
Error : unable to load R code in package ‘CF’
ERROR: lazy loading failed for package ‘CF’
* removing ‘/Users/PJO/Library/R/3.4/library/CF’
* restoring previous ‘/Users/PJO/Library/R/3.4/library/CF’
Exited with status 1.
My search has shown that other developers have experienced similar problems. I believe that it connected to (a) devtools and some (b) lingering code. I cannot prove it.
The following efforts have not worked: (1) restarting R, (2) removing invisible files, .R*, (3) rebooting RStudio, (4) debugging all functions with RStudio debug() before committing them to the R package, ... . The error suggests that I have not loaded all the data or required libraries. The above error directs attention to the R library "gapminder." It calls "aes" therefore, it should load. With or without loading "gapminder," I obtain the same error. So, I suspect some hidden files are lurking in the background.
To compare, I tested an old version of my CF package. It works:
==> R CMD INSTALL --preclean --no-multiarch --with-keep.source CF
installing to library ‘/Users/PJO/Library/R/3.4/library’
installing source package ‘CF’ ...
** R
** data
* moving datasets to lazyload DB
** inst
** preparing package for lazy loading
** help
* installing help indices
** building package indices
** testing if installed package can be loaded
DONE (CF)
Other attempts include using browser() and traceback() from Rstudio debug() fail. They fail because of the Clean and Rebuild fails before debug() is called.
Some devtools::check() failures for my latest CF package:
The Title field should be in title case, current version then in title case:
‘Stochastic traffic performance and car-following modeling tools’
‘Stochastic Traffic Performance and Car-Following Modeling Tools’
── Install failure ─────────────────────────────────────────────────────────────────────────
checking for empty or unneeded directories
Removed empty directory ‘CF/inst/extdata’
Removed empty directory ‘CF/inst’
looking to see if a ‘data/datalist’ file should be added
building ‘CF_0.1.0.tar.gz’
Some devtools::check() failures for my older CF package:
The Title field should be in title case, current version then in title case:
‘A package for performing analyses with stochastic traffic performance and car-following models’
‘A Package for Performing Analyses with Stochastic Traffic Performance and Car-Following Models’
plotfollow2: no visible binding for global variable ‘leff’
Undefined global functions or variables:
leff
These errors do not cause Clean and Rebuild error.
As you can see, I have run out of things to try. For another, I am experienced enough to know if I am overlooking something. For example, I am taking the Title problem seriously. To be honest, the suggested corrective action does not make sense to me.
Help would be greatly appreciated.
Paul