Error(s) in re-building vignettes:
  ...
--- re-building ‘biogas_quick_start.Rnw’ using knitr
Error: processing vignette 'biogas_quick_start.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'biogas_quick_start.tex' failed.
LaTeX errors:
! Undefined control sequence.
l.234 \hlkwd{library}\hldef
                           {(biogas)}
? 
! Emergency stop.
! Emergency stop.
l.234 
      
End of file on the terminal!

!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘biogas_quick_start.Rnw’

--- re-building ‘calcBgMan_function.Rnw’ using knitr
Error: processing vignette 'calcBgMan_function.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'calcBgMan_function.tex' failed.
LaTeX errors:
! Undefined control sequence.
l.163 \hlkwd{data}\hldef
                        {(}\hlsng{"sludgeTwoBiogas"}\hldef{)}
? 
! Emergency stop.
! Emergency stop.
l.163 
      
End of file on the terminal!

!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘calcBgMan_function.Rnw’

--- re-building ‘calcBgVol_function.Rnw’ using knitr
Error: processing vignette 'calcBgVol_function.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'calcBgVol_function.tex' failed.
LaTeX errors:
! Undefined control sequence.
l.146 \hlkwd{data}\hldef
                        {(}\hlsng{"s3lcombo"}\hldef{)}
? 
! Emergency stop.
! Emergency stop.
l.146 
      
End of file on the terminal!

!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘calcBgVol_function.Rnw’

--- re-building ‘predBg_function.Rnw’ using knitr
Error: processing vignette 'predBg_function.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'predBg_function.tex' failed.
LaTeX errors:
! Undefined control sequence.
l.88   \hlkwd{install.packages}\hldef
                                     {(}\hlsng{"biogas"}\hldef{)}
? 
! Emergency stop.
! Emergency stop.
l.88 
     
End of file on the terminal!

!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘predBg_function.Rnw’

SUMMARY: processing the following files failed:
  ‘biogas_quick_start.Rnw’ ‘calcBgMan_function.Rnw’
  ‘calcBgVol_function.Rnw’ ‘predBg_function.Rnw’

Error: Vignette re-building failed.
Execution halted