Running examples in ‘ggloop-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: ggloop
> ### Title: Create ggplot plots in a loop.
> ### Aliases: ggloop
> 
> ### ** Examples
> 
> # 1. Return all possible x-y combinations.
> plots <- ggloop(data = mtcars,
+                 mappings = aes_loop(x = mpg:carb, y = mpg:carb))
> names(plots)
 [1] "x.mpg_y.cyl"   "x.mpg_y.disp"  "x.mpg_y.hp"    "x.mpg_y.drat" 
 [5] "x.mpg_y.wt"    "x.mpg_y.qsec"  "x.mpg_y.vs"    "x.mpg_y.am"   
 [9] "x.mpg_y.gear"  "x.mpg_y.carb"  "x.cyl_y.disp"  "x.cyl_y.hp"   
[13] "x.cyl_y.drat"  "x.cyl_y.wt"    "x.cyl_y.qsec"  "x.cyl_y.vs"   
[17] "x.cyl_y.am"    "x.cyl_y.gear"  "x.cyl_y.carb"  "x.disp_y.hp"  
[21] "x.disp_y.drat" "x.disp_y.wt"   "x.disp_y.qsec" "x.disp_y.vs"  
[25] "x.disp_y.am"   "x.disp_y.gear" "x.disp_y.carb" "x.hp_y.drat"  
[29] "x.hp_y.wt"     "x.hp_y.qsec"   "x.hp_y.vs"     "x.hp_y.am"    
[33] "x.hp_y.gear"   "x.hp_y.carb"   "x.drat_y.wt"   "x.drat_y.qsec"
[37] "x.drat_y.vs"   "x.drat_y.am"   "x.drat_y.gear" "x.drat_y.carb"
[41] "x.wt_y.qsec"   "x.wt_y.vs"     "x.wt_y.am"     "x.wt_y.gear"  
[45] "x.wt_y.carb"   "x.qsec_y.vs"   "x.qsec_y.am"   "x.qsec_y.gear"
[49] "x.qsec_y.carb" "x.vs_y.am"     "x.vs_y.gear"   "x.vs_y.carb"  
[53] "x.am_y.gear"   "x.am_y.carb"   "x.gear_y.carb"
> # [1] "x.mpg_y.cyl"   "x.mpg_y.disp"  "x.mpg_y.hp"    "x.mpg_y.drat"
> # [5] "x.mpg_y.wt"    "x.mpg_y.qsec"  "x.mpg_y.vs"    "x.mpg_y.am"
> # [9] "x.mpg_y.gear"  "x.mpg_y.carb"  "x.cyl_y.disp"  "x.cyl_y.hp"
> # [13] "x.cyl_y.drat"  "x.cyl_y.wt"    "x.cyl_y.qsec"  "x.cyl_y.vs"
> # [17] "x.cyl_y.am"    "x.cyl_y.gear"  "x.cyl_y.carb"  "x.disp_y.hp"
> # [21] "x.disp_y.drat" "x.disp_y.wt"   "x.disp_y.qsec" "x.disp_y.vs"
> # [25] "x.disp_y.am"   "x.disp_y.gear" "x.disp_y.carb" "x.hp_y.drat"
> # [29] "x.hp_y.wt"     "x.hp_y.qsec"   "x.hp_y.vs"     "x.hp_y.am"
> # [33] "x.hp_y.gear"   "x.hp_y.carb"   "x.drat_y.wt"   "x.drat_y.qsec"
> # [37] "x.drat_y.vs"   "x.drat_y.am"   "x.drat_y.gear" "x.drat_y.carb"
> # [41] "x.wt_y.qsec"   "x.wt_y.vs"     "x.wt_y.am"     "x.wt_y.gear"
> # [45] "x.wt_y.carb"   "x.qsec_y.vs"   "x.qsec_y.am"   "x.qsec_y.gear"
> # [49] "x.qsec_y.carb" "x.vs_y.am"     "x.vs_y.gear"   "x.vs_y.carb"
> # [53] "x.am_y.gear"   "x.am_y.carb"   "x.gear_y.carb"
> 
> plots$x.mpg_y.hp + ggplot2::geom_point()
Error in grid.Call.graphics(C_setviewport, vp, TRUE) : 
  VECTOR_ELT() can only be applied to a 'list', not a 'double'
Calls: <Anonymous> ... lapply -> FUN -> push.vp.viewport -> grid.Call.graphics
Execution halted