Error(s) in re-building vignettes:
--- re-building ‘asmapvignette.Rnw’ using knitr
Error: processing vignette 'asmapvignette.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'asmapvignette.tex' failed.
LaTeX errors:
! Undefined control sequence.
\tabu@cleanup ...bu@naturalX =\tabu@naturalX@save 
                                                  \let \tabu@naturalXmax \ta...
l.109 \end{tabu}
                \\[5mm]
! Emergency stop.
\tabu@cleanup ...bu@naturalX =\tabu@naturalX@save 
                                                  \let \tabu@naturalXmax \ta...
l.109 \end{tabu}
                \\[5mm]
!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘asmapvignette.Rnw’

SUMMARY: processing the following file failed:
  ‘asmapvignette.Rnw’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
--- re-building ‘asmapvignette.Rnw’ using knitr
Error: processing vignette 'asmapvignette.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'asmapvignette.tex' failed.
LaTeX errors:
! Undefined control sequence.
\tabu@cleanup ...bu@naturalX =\tabu@naturalX@save 
                                                  \let \tabu@naturalXmax \ta...
l.109 \end{tabu}
                \\[5mm]
! Emergency stop.
\tabu@cleanup ...bu@naturalX =\tabu@naturalX@save 
                                                  \let \tabu@naturalXmax \ta...
l.109 \end{tabu}
                \\[5mm]
!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘asmapvignette.Rnw’

SUMMARY: processing the following file failed:
  ‘asmapvignette.Rnw’

Error: Vignette re-building failed.
Execution halted