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

--- re-building ‘pez-pglmm-overview.Rnw’ using knitr
Quitting from lines 181-184 (pez-pglmm-overview.Rnw) 
Error: processing vignette 'pez-pglmm-overview.Rnw' failed with diagnostics:
Estimation of B failed. Check for lack of variation in Y. You could try with a smaller s2.init, but this might not help.
--- failed re-building ‘pez-pglmm-overview.Rnw’

SUMMARY: processing the following file failed:
  ‘pez-pglmm-overview.Rnw’

Error: Vignette re-building failed.
Execution halted
Error(s) in re-building vignettes:
  ...
--- re-building ‘pez-intro.Rnw’ using knitr
--- finished re-building ‘pez-intro.Rnw’

--- re-building ‘pez-pglmm-overview.Rnw’ using knitr
Quitting from lines 181-184 (pez-pglmm-overview.Rnw) 
Error: processing vignette 'pez-pglmm-overview.Rnw' failed with diagnostics:
Estimation of B failed. Check for lack of variation in Y. You could try with a smaller s2.init, but this might not help.
--- failed re-building ‘pez-pglmm-overview.Rnw’

SUMMARY: processing the following file failed:
  ‘pez-pglmm-overview.Rnw’

Error: Vignette re-building failed.
Execution halted