Error(s) in re-building vignettes:
--- re-building ‘an_introduction_to_lifecontingencies_package.Rnw’ using Sweave
Package:  lifecontingencies
Authors:  Giorgio Alfredo Spedicato [aut, cre]
    (<https://orcid.org/0000-0002-0315-8888>),
  Christophe Dutang [ctb] (<https://orcid.org/0000-0001-6732-1501>),
  Reinhold Kainhofer [ctb] (<https://orcid.org/0000-0002-7895-1311>),
  Kevin J Owens [ctb],
  Ernesto Schirmacher [ctb],
  Gian Paolo Clemente [ctb] (<https://orcid.org/0000-0001-6795-4595>),
  Ivan Williams [ctb]
Version:  1.3.6
Date:     2019-03-05 23:50:03 UTC
BugReport: http://github.com/spedygiorgio/lifecontingencies/issues

Loading required package: markovchain
Package:  markovchain
Version:  0.8.4
Date:     2020-03-12
BugReport: http://github.com/spedygiorgio/markovchain/issues

Loading required package: parallel
--- finished re-building 'an_introduction_to_lifecontingencies_package.Rnw'

--- re-building ‘mortality_projection.Rnw’ using Sweave
Loading required package: forecast
This is demography 1.22 

Package:  lifecontingencies
Authors:  Giorgio Alfredo Spedicato [aut, cre]
    (<https://orcid.org/0000-0002-0315-8888>),
  Christophe Dutang [ctb] (<https://orcid.org/0000-0001-6732-1501>),
  Reinhold Kainhofer [ctb] (<https://orcid.org/0000-0002-7895-1311>),
  Kevin J Owens [ctb],
  Ernesto Schirmacher [ctb],
  Gian Paolo Clemente [ctb] (<https://orcid.org/0000-0001-6795-4595>),
  Ivan Williams [ctb]
Version:  1.3.6
Date:     2019-03-05 23:50:03 UTC
BugReport: http://github.com/spedygiorgio/lifecontingencies/issues

Loading required package: StMoMo
Loading required package: gnm
--- finished re-building ‘mortality_projection.Rnw’

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

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

--- re-building ‘introToLifecontingencies.Rmd’ using rmarkdown
Package:  lifecontingencies
Authors:  Giorgio Alfredo Spedicato [aut, cre]
    (<https://orcid.org/0000-0002-0315-8888>),
  Christophe Dutang [ctb] (<https://orcid.org/0000-0001-6732-1501>),
  Reinhold Kainhofer [ctb] (<https://orcid.org/0000-0002-7895-1311>),
  Kevin J Owens [ctb],
  Ernesto Schirmacher [ctb],
  Gian Paolo Clemente [ctb] (<https://orcid.org/0000-0001-6795-4595>),
  Ivan Williams [ctb]
Version:  1.3.6
Date:     2019-03-05 23:50:03 UTC
BugReport: http://github.com/spedygiorgio/lifecontingencies/issues

Loading required package: forecast
This is demography 1.22 

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

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

SUMMARY: processing the following files failed:
  ‘PensionPlanVal.Rmd’ ‘compute-detail.Rmd’
  ‘introToLifecontingencies.Rmd’ ‘pensionfunding.Rmd’

Error: Vignette re-building failed.
Execution halted