Error(s) in re-building vignettes:
--- re-building ‘checking_function_inputs.Rmd’ using rmarkdown
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 'checking_function_inputs.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘checking_function_inputs.Rmd’

--- re-building ‘checklists.Rmd’ using rmarkdown
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 'checklists.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘checklists.Rmd’

--- re-building ‘exercise_answers.Rmd’ using rmarkdown
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 'exercise_answers.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘exercise_answers.Rmd’

--- re-building ‘introduction.Rmd’ using rmarkdown
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 'introduction.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘introduction.Rmd’

SUMMARY: processing the following files failed:
  ‘checking_function_inputs.Rmd’ ‘checklists.Rmd’
  ‘exercise_answers.Rmd’ ‘introduction.Rmd’

Error: Vignette re-building failed.
Execution halted