Error(s) in re-building vignettes:
--- re-building 'case-study-collins-2016.Rmd' using rmarkdown
--- finished re-building 'case-study-collins-2016.Rmd'

--- re-building 'tutorial-010-quick-start.Rmd' using rmarkdown
--- finished re-building 'tutorial-010-quick-start.Rmd'

--- re-building 'tutorial-020-replication.Rmd' using rmarkdown
--- finished re-building 'tutorial-020-replication.Rmd'

--- re-building 'tutorial-030-steady-state-comps.Rmd' using rmarkdown
--- finished re-building 'tutorial-030-steady-state-comps.Rmd'

--- re-building 'tutorial-040-pulse-drip-events.Rmd' using rmarkdown
--- finished re-building 'tutorial-040-pulse-drip-events.Rmd'

--- re-building 'tutorial-050-fixed-effects.Rmd' using rmarkdown
--- finished re-building 'tutorial-050-fixed-effects.Rmd'

--- re-building 'tutorial-060-units-priors.Rmd' using rmarkdown
--- finished re-building 'tutorial-060-units-priors.Rmd'

+-+tutorial-060-units-priors.html
--- re-building 'tutorial-070-prior-predictive-checks.Rmd' using rmarkdown
--- finished re-building 'tutorial-070-prior-predictive-checks.Rmd'

--- re-building 'tutorial-080-mcmc-output-format.Rmd' using rmarkdown
--- finished re-building 'tutorial-080-mcmc-output-format.Rmd'

--- re-building 'tutorial-090-post-run-analyses.Rmd' using rmarkdown
--- finished re-building 'tutorial-090-post-run-analyses.Rmd'

--- re-building 'tutorial-100-posterior-predictive-checks.Rmd' using rmarkdown
--- finished re-building 'tutorial-100-posterior-predictive-checks.Rmd'

--- re-building 'tutorial-110-derived-parameters.Rmd' using rmarkdown
--- finished re-building 'tutorial-110-derived-parameters.Rmd'

--- re-building 'tutorial-120-howto-simulations.Rmd' using rmarkdown
--- finished re-building 'tutorial-120-howto-simulations.Rmd'

--- re-building 'tutorial-130-parameter-identifiability.Rmd' using rmarkdown
--- finished re-building 'tutorial-130-parameter-identifiability.Rmd'

SUMMARY: processing the following file failed:
  'tutorial-060-units-priors.Rmd'

Error: Vignette re-building failed.
Execution halted