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

> ### Name: gsi_tiles
> ### Title: Add a tile layer from GSI
> ### Aliases: gsi_tiles
> ### Keywords: datasets
> 
> ### ** Examples
> 
> names(gsi_tiles)
 [1] "standard"             "pale"                 "english"             
 [4] "lcm25k_2012"          "lcm25k"               "ccm1"                
 [7] "ccm2"                 "vbm"                  "vbmd_bm"             
[10] "vbmd_colorrel"        "vbmd_pm"              "vlcd"                
[13] "lum200k"              "lake1"                "lakedata"            
[16] "blank"                "seamlessphoto"        "ortho"               
[19] "airphoto"             "gazo4"                "gazo3"               
[22] "gazo2"                "gazo1"                "ort_old10"           
[25] "ort_USA10"            "ort_riku10"           "relief"              
[28] "anaglyphmap_color"    "anaglyphmap_gray"     "hillshademap"        
[31] "earthhillshade"       "slopemap"             "slopezone1map"       
[34] "afm"                  "lcmfc2"               "lcmfc1"              
[37] "swale"                "cp"                   "jikizu2015_chijiki_d"
[40] "jikizu2015_chijiki_i" "jikizu2015_chijiki_f" "jikizu2015_chijiki_h"
[43] "jikizu2015_chijiki_z" "jikizu_chijikid"      "jikizu_chijikii"     
[46] "jikizu_chijikif"      "jikizu_chijikih"      "jikizu_chijikiz"     
> require("leaflet")
Loading required package: leaflet
> gsi_tiles[[1]]
> 
> gsi_tiles[[1]] %>%
+   addCircles(
+     data = sf::st_transform(extreme_points %>%
+       purrr::reduce(c),
+       crs = 4326))
Warning in CPL_transform(x, crs, aoi, pipeline, reverse, desired_accuracy,  :
  GDAL Error 1: No PROJ.4 translation for source SRS, coordinate transformation initialization has failed.
Error in CPL_transform(x, crs, aoi, pipeline, reverse, desired_accuracy,  : 
  OGRCreateCoordinateTransformation() returned NULL: PROJ available?
Calls: %>% ... st_transform.sfc -> st_sfc -> structure -> CPL_transform
Execution halted