Error(s) in re-building vignettes:
--- re-building ‘tbm_supplement.Rnw’ using knitr

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular; attempting approx solution

warning: solve(): system is singular (rcond: 9.83748e-19); attempting approx solution

warning: solve(): system is singular (rcond: 9.83748e-19); attempting approx solution

warning: solve(): system is singular (rcond: 9.83748e-19); attempting approx solution

warning: solve(): system is singular (rcond: 9.83748e-19); attempting approx solution

warning: solve(): system is singular (rcond: 9.83748e-19); attempting approx solution
Error: processing vignette 'tbm_supplement.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'tbm_supplement.tex' failed.
LaTeX errors:
! LaTeX Error: Missing \begin{document}.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
! Emergency stop.
 ...                                              
                                                  
l.170  \DeclareMathOperator{\Chi1}{\chi^2_1}
                                            
!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘tbm_supplement.Rnw’

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

Error: Vignette re-building failed.
Execution halted