Error(s) in re-building vignettes:
--- re-building ‘ggrepel.Rmd’ using rmarkdown
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning: Removed 1 rows containing missing values (geom_vline).
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Scale for 'y' is already present. Adding another scale for 'y', which will
replace the existing scale.
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning: Removed 3 rows containing missing values (geom_label_repel).
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
Warning in hook_png(before, options, envir, "pngquant", function(x) { :
  cannot find pngquant; please install and put it in PATH
dyld: lazy symbol binding failed: Symbol not found: ____chkstk_darwin
  Referenced from: /usr/local/bin/pandoc (which was built for Mac OS X 10.15)
  Expected in: /usr/lib/libSystem.B.dylib

dyld: Symbol not found: ____chkstk_darwin
  Referenced from: /usr/local/bin/pandoc (which was built for Mac OS X 10.15)
  Expected in: /usr/lib/libSystem.B.dylib

Error: processing vignette 'ggrepel.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘ggrepel.Rmd’

SUMMARY: processing the following file failed:
  ‘ggrepel.Rmd’

Error: Vignette re-building failed.
Execution halted