Error(s) in re-building vignettes:
sh: line 1: 78194 Abort trap: 6           '/Library/Frameworks/R.framework/Resources/bin/R' --vanilla --slave > '/tmp/RtmplqJG0s/file1316d31b9af64' 2>&1 < '/tmp/RtmplqJG0s/file1316d15a9e7bd'
--- re-building ‘discoverYourData.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
Loading required package: xgboost
Loading required package: Matrix
Loading required package: data.table
Loading required package: vcd
Loading required package: grid
OMP: Error #15: Initializing libomp.dylib, but found libomp.dylib already initialized.
OMP: Hint This means that multiple copies of the OpenMP runtime have been linked into the program. That is dangerous, since it can degrade performance or cause incorrect results. The best thing to do is to ensure that only a single OpenMP runtime is linked into the process, e.g. by avoiding static linking of the OpenMP runtime in any library. As an unsafe, unsupported, undocumented workaround you can set the environment variable KMP_DUPLICATE_LIB_OK=TRUE to allow the program to continue to execute, but that may cause crashes or silently produce incorrect results. For more information, please see http://openmp.llvm.org/
sh: line 1: 78201 Abort trap: 6           '/Library/Frameworks/R.framework/Resources/bin/R' --vanilla --slave > '/tmp/RtmplqJG0s/file1316d6e4b79ed' 2>&1 < '/tmp/RtmplqJG0s/file1316d1d31ef2d'
--- re-building ‘xgboostPresentation.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
Loading required package: xgboost
OMP: Error #15: Initializing libomp.dylib, but found libomp.dylib already initialized.
OMP: Hint This means that multiple copies of the OpenMP runtime have been linked into the program. That is dangerous, since it can degrade performance or cause incorrect results. The best thing to do is to ensure that only a single OpenMP runtime is linked into the process, e.g. by avoiding static linking of the OpenMP runtime in any library. As an unsafe, unsupported, undocumented workaround you can set the environment variable KMP_DUPLICATE_LIB_OK=TRUE to allow the program to continue to execute, but that may cause crashes or silently produce incorrect results. For more information, please see http://openmp.llvm.org/
sh: line 1: 78208 Abort trap: 6           '/Library/Frameworks/R.framework/Resources/bin/R' --vanilla --slave > '/tmp/RtmplqJG0s/file1316dfa77630' 2>&1 < '/tmp/RtmplqJG0s/file1316d3b405157'
--- re-building ‘xgboostfromJSON.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
OMP: Error #15: Initializing libomp.dylib, but found libomp.dylib already initialized.
OMP: Hint This means that multiple copies of the OpenMP runtime have been linked into the program. That is dangerous, since it can degrade performance or cause incorrect results. The best thing to do is to ensure that only a single OpenMP runtime is linked into the process, e.g. by avoiding static linking of the OpenMP runtime in any library. As an unsafe, unsupported, undocumented workaround you can set the environment variable KMP_DUPLICATE_LIB_OK=TRUE to allow the program to continue to execute, but that may cause crashes or silently produce incorrect results. For more information, please see http://openmp.llvm.org/
sh: line 1: 78215 Abort trap: 6           '/Library/Frameworks/R.framework/Resources/bin/R' --vanilla --slave > '/tmp/RtmplqJG0s/file1316d507f7de2' 2>&1 < '/tmp/RtmplqJG0s/file1316d6221a9b7'
--- re-building ‘xgboost.Rnw’ using knitr
Loading required package: knitr
OMP: Error #15: Initializing libomp.dylib, but found libomp.dylib already initialized.
OMP: Hint This means that multiple copies of the OpenMP runtime have been linked into the program. That is dangerous, since it can degrade performance or cause incorrect results. The best thing to do is to ensure that only a single OpenMP runtime is linked into the process, e.g. by avoiding static linking of the OpenMP runtime in any library. As an unsafe, unsupported, undocumented workaround you can set the environment variable KMP_DUPLICATE_LIB_OK=TRUE to allow the program to continue to execute, but that may cause crashes or silently produce incorrect results. For more information, please see http://openmp.llvm.org/
SUMMARY: processing the following files failed:
  ‘discoverYourData.Rmd’ ‘xgboostPresentation.Rmd’
  ‘xgboostfromJSON.Rmd’ ‘xgboost.Rnw’

Error: Vignette re-building failed.
Execution halted