Error(s) in re-building vignettes:
  ...
--- re-building ‘flexsurv.Rnw’ using knitr
Error: processing vignette ‘flexsurv.Rnw’ failed with diagnostics:
Running ‘texi2dvi’ on ‘flexsurv.tex’ failed.
LaTeX errors:
! Missing $ inserted.
<inserted text> 
                $
l.766 ...weibull(x, shape = shape, scale = scale ^
                                                   {-1 / shape}, log = log)
! Emergency stop.
<inserted text> 
                $
l.766 ...weibull(x, shape = shape, scale = scale ^
                                                   {-1 / shape}, log = log)
!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘flexsurv.Rnw’

--- re-building ‘multistate.Rnw’ using knitr

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

Joining, by = c("time", "model", "state", "val")
Error: processing vignette ‘multistate.Rnw’ failed with diagnostics:
Running ‘texi2dvi’ on ‘multistate.tex’ failed.
LaTeX errors:
! Missing $ inserted.
<inserted text> 
                $
l.321 mod_
          nobos_bos <- flexsurvreg(Surv(years, status) ~ 1, subset=(trans==1),
! Emergency stop.
<inserted text> 
                $
l.321 mod_
          nobos_bos <- flexsurvreg(Surv(years, status) ~ 1, subset=(trans==1),
!  ==> Fatal error occurred, no output PDF file produced!
--- failed re-building ‘multistate.Rnw’

--- re-building ‘distributions.Rnw’ using Sweave
--- finished re-building ‘distributions.Rnw’

--- re-building ‘flexsurv-examples.Rnw’ using Sweave
Forming integrated rmst function...
Forming integrated mean function...
Loading required package: TH.data
Loading required package: MASS

Attaching package: ‘MASS’

The following object is masked from ‘package:dplyr’:

    select


Attaching package: ‘TH.data’

The following object is masked from ‘package:MASS’:

    geyser

--- finished re-building ‘flexsurv-examples.Rnw’

SUMMARY: processing the following files failed:
  ‘flexsurv.Rnw’ ‘multistate.Rnw’

Error: Vignette re-building failed.
Execution halted