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

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

--- re-building ‘example1_intro.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 'example1_intro.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘example1_intro.Rmd’

--- re-building ‘example2_join.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 'example2_join.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘example2_join.Rmd’

--- re-building ‘example3_reshape.Rmd’ using rmarkdown
Warning in melt.data.table(data = dt, id = group, variable.name = name,  :
  'measure.vars' [dob_child1, dob_child2, dob_child3, gender_child1, ...] are not all of the same type. By order of hierarchy, the molten data value column will be of type 'character'. All measure variables not of type 'character' will be coerced too. Check DETAILS in ?melt.data.table for more on coercion.
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 'example3_reshape.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘example3_reshape.Rmd’

--- re-building ‘example4_nest.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 'example4_nest.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘example4_nest.Rmd’

--- re-building ‘example5_fst.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 'example5_fst.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘example5_fst.Rmd’

--- re-building ‘example6_dt.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 'example6_dt.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘example6_dt.Rmd’

SUMMARY: processing the following files failed:
  ‘chinese_tutorial.Rmd’ ‘english_tutorial.Rmd’ ‘example1_intro.Rmd’
  ‘example2_join.Rmd’ ‘example3_reshape.Rmd’ ‘example4_nest.Rmd’
  ‘example5_fst.Rmd’ ‘example6_dt.Rmd’

Error: Vignette re-building failed.
Execution halted