Error in re-building vignettes:
  ...
You are recommended to install the tinytex package to build PDF.FALSE
Latexmk: This is Latexmk, John Collins, 1 January 2015, version: 4.41.
Rule 'pdflatex': File changes, etc:
   Changed files, or newly in use since previous run(s):
      'RcppArmadillo-sparseMatrix.aux'
   Non-existent destination files:
      'RcppArmadillo-sparseMatrix.pdf'
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Run number 1 of rule 'pdflatex'
------------
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Running 'pdflatex  -halt-on-error -interaction=batchmode -recorder  "RcppArmadillo-sparseMatrix.tex"'
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Latexmk: applying rule 'pdflatex'...
This is pdfTeX, Version 3.14159265-2.6-1.40.19 (TeX Live 2018/Debian) (preloaded format=pdflatex)
 restricted \write18 enabled.
entering extended mode
Latexmk: List of undefined refs and citations:
  Citation `CRAN:Matrix' on page 1 undefined on input line 71
  Citation `CRAN:RcppArmadillo' on page 1 undefined on input line 96
  Citation `Eddelbuettel+Sanderson:2014:RcppArmadillo' on page 1 undefined on input line 96
  Citation `Sanderson+Curtin:2016' on page 1 undefined on input line 73
  Citation `Sanderson:2010:Armadillo' on page 1 undefined on input line 73
  Reference `LastPage' on page 1 undefined on input line 147
  Reference `mdf@pagelabel-27' on page 10 undefined on input line 831
  Reference `mdf@pagelabel-28' on page 10 undefined on input line 851
Latexmk: Summary of warnings:
  Latex failed to resolve 3 reference(s)
  Latex failed to resolve 5 citation(s)
Collected error summary (may duplicate other messages):
  pdflatex: Command for 'pdflatex' gave return code 256
Latexmk: Use the -f option to force complete processing,
 unless error was exceeding maximum runs of latex/pdflatex.
Latexmk: Errors, so I did not complete making targets

Latexmk, John Collins, 1 January 2015. Version 4.41
Warning: Your latexmk version seems to be too low. You may need to update the latexmk package or your LaTeX distribution.
! LaTeX Error: Lonely \item--perhaps a missing list environment.

Error: processing vignette ‘RcppArmadillo-sparseMatrix.Rmd’ failed with diagnostics:
Failed to compile RcppArmadillo-sparseMatrix.tex. See RcppArmadillo-sparseMatrix.log for more info.
Execution halted