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

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

--- re-building ‘intro.Rmd’ using rmarkdown
Loading required package: survival
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 'intro.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘intro.Rmd’

--- re-building ‘psm.Rmd’ using rmarkdown
Loading required package: survival
Warning: Survival curves crossed 0.06 percent of the time.
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 'psm.Rmd' failed with diagnostics:
pandoc document conversion failed with error 6
--- failed re-building ‘psm.Rmd’

SUMMARY: processing the following files failed:
  ‘ctstm.Rmd’ ‘icea.Rmd’ ‘intro.Rmd’ ‘psm.Rmd’

Error: Vignette re-building failed.
Execution halted